https://en.wikivet.net/api.php?action=feedcontributions&feedformat=atom&user=Amycartmel 2026-05-02T12:29:13Z User contributions MediaWiki 1.35.0 https://en.wikivet.net/index.php?title=Spermatogenesis_and_Spermiation_-_Anatomy_%26_Physiology&diff=32625 2008-08-30T15:44:19Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> ==Introduction==<br /> Unlike the female production of gametes which occurs entirely before birth with gamete maturation occurring in a pulsatile fashion after puberty, male individuals produce gametes continuously from puberty onwards for the rest of their reproductive lives and the release of the gametes is constant. Spermatogenesis is the process of producing sperm, and it occurs in three phases:<br /> *Proliferative phase<br /> *Meiotic phase<br /> *Differentiation phase / spermiogenesis<br /> <br /> ==The Spermatogenic Cycle==<br /> [[Image:spermatogenesis.jpg|thumb|right|150px|Spermatogenesis Copyright Amy Cartmel 2008]]<br /> <br /> *Spermatogenesis occurs in the Seminipherous tubules of the testes. <br /> *Sertoli cells found within the seminipherous tubules play a vital role in the production of gametes. Sertoli cells are support cell within the seminipherous tubules. They are anchored to the basement membrane and reach all the way to the lumen of the tubules. The junctional complexes between neighbouring sertoli cells make up the ‘’’blood-testes barrier’’’ which prevents autoimmune reactions against haploid spermatids and spermatozoa by providing an immunologically privileged site. The blood-testes barrier splits the seminipherous epithelium into two main sections; the basal compartment where spermatogonia develop and the adluminal compartment where spermatocytes, spermatids and spermatozoa develop.<br /> *Spermatogenesis occurs in three phases:<br /> **'''Proliferation''' - Spermatogonia undergo many mitotic divisions in order to maintain the spermatogonia population in order for spermatogenesis to be continuously producing sperm. <br /> **'''Meiosis''' - <br /> **'''Differenciation''' -<br /> <br /> ==Hormonal Control of Spermatogenesis==<br /> The production of sperm is controlled by hormones influencing sertoli cells rather than sperm cells directly. Hormonal control is via the two gonadotrophins Luteinising hormone (LH) and follicle stimulating hormone (FSH).<br /> *LH acts on the interstitial Leydig cells stimulating them to produce the androgen testosterone.<br /> *FSH acts on the Sertoli cells within the seminipherous tubules stimulating production of Androgen Binding Protein as well as Inhibin</div>

Amycartmel https://en.wikivet.net/index.php?title=Spermatogenesis_and_Spermiation_-_Anatomy_%26_Physiology&diff=32444 2008-08-29T08:42:33Z

<p>Amycartmel: /* The Spermatogenic Cycle */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> ==Introduction==<br /> Unlike the female production of gametes which occurs entirely before birth with gamete maturation occurring in a pulsatile fashion after puberty, male individuals produce gametes continuously from puberty onwards for the rest of their reproductive lives and the release of the gametes is constant. Spermatogenesis is the process of producing sperm, and it occurs in three phases:<br /> *Proliferative phase<br /> *Meiotic phase<br /> *Differentiation phase / spermiogenesis<br /> <br /> ==The Spermatogenic Cycle==<br /> [[Image:spermatogenesis.jpg|thumb|right|150px|Spermatogenesis Copyright Amy Cartmel 2008]]<br /> <br /> *Spermatogenesis occurs in the Seminipherous tubules of the testes. <br /> *Sertoli cells found within the seminipherous tubules play a vital role in the production of gametes. Sertoli cells are support cell within the seminipherous tubules. They are anchored to the basement membrane and reach all the way to the lumen of the tubules. The junctional complexes between neighbouring sertoli cells make up the ‘’’blood-testes barrier’’’ which prevents autoimmune reactions against haploid spermatids and spermatozoa by providing an immunologically privileged site. The blood-testes barrier splits the seminipherous epithelium into two main sections; the basal compartment where spermatogonia develop and the adluminal compartment where spermatocytes, spermatids and spermatozoa develop.<br /> *Spermatogenesis occurs in three phases:<br /> **’’’Proliferation’’’ - Spermatogonia undergo many mitotic divisions in order to maintain the spermatogonia population in order for spermatogenesis to be continuously producing sperm. <br /> **’’’Meiosis’’’ - <br /> **’’’Differenciation’’’ -<br /> <br /> ==Hormonal Control of Spermatogenesis==<br /> The production of sperm is controlled by hormones influencing sertoli cells rather than sperm cells directly. Hormonal control is via the two gonadotrophins Luteinising hormone (LH) and follicle stimulating hormone (FSH).<br /> *LH acts on the interstitial Leydig cells stimulating them to produce the androgen testosterone.<br /> *FSH acts on the Sertoli cells within the seminipherous tubules stimulating production of Androgen Binding Protein as well as Inhibin</div>

Amycartmel https://en.wikivet.net/index.php?title=Spermatogenesis_and_Spermiation_-_Anatomy_%26_Physiology&diff=32443 2008-08-29T08:41:30Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> ==Introduction==<br /> Unlike the female production of gametes which occurs entirely before birth with gamete maturation occurring in a pulsatile fashion after puberty, male individuals produce gametes continuously from puberty onwards for the rest of their reproductive lives and the release of the gametes is constant. Spermatogenesis is the process of producing sperm, and it occurs in three phases:<br /> *Proliferative phase<br /> *Meiotic phase<br /> *Differentiation phase / spermiogenesis<br /> <br /> ==The Spermatogenic Cycle==<br /> [[Image:spermatogenesis.jpg|thumb|right|150px|Spermatogenesis Copyright Amy Cartmel 2008]]<br /> <br /> *Spermatogenesis occurs in the Seminipherous tubules of the testes. <br /> *Sertoli cells found within the seminipherous tubules play a vital role in the production of gametes. Sertoli cells are support cell within the seminipherous tubules. They are anchored to the basement membrane and reach all the way to the lumen of the tubules. The junctional complexes between neighbouring sertoli cells make up the ‘’’blood-testes barrier’’’ which prevents autoimmune reactions against haploid spermatids and spermatozoa by providing an immunologically privileged site. The blood-testes barrier splits the seminipherous epithelium into two main sections; the basal compartment where spermatogonia develop and the adluminal compartment where spermatocytes, spermatids and spermatozoa develop.<br /> *Spermatogenesis occurs in three phases:<br /> **’’’Proliferation’’’ - Spermatogonia undergo many mitotic divisions in order to maintain the spermatogonia population in order for spermatogenesis to be continuously producing sperm. <br /> **’’’Meiosis’’’ - <br /> <br /> ==Hormonal Control of Spermatogenesis==<br /> The production of sperm is controlled by hormones influencing sertoli cells rather than sperm cells directly. Hormonal control is via the two gonadotrophins Luteinising hormone (LH) and follicle stimulating hormone (FSH).<br /> *LH acts on the interstitial Leydig cells stimulating them to produce the androgen testosterone.<br /> *FSH acts on the Sertoli cells within the seminipherous tubules stimulating production of Androgen Binding Protein as well as Inhibin</div>

Amycartmel https://en.wikivet.net/index.php?title=Accessory_Sex_Glands_-_Anatomy_%26_Physiology&diff=32424 2008-08-29T01:50:26Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> ==Introduction==<br /> Accessory sex glands are all found along the length of the pelvic urethra. They produce secretions containing lots of different components many of which can be found also the blood. One of the most important substances is fructose which provides an energy source for sperm. Along with providing nutrition for spermatozoa sex gland secretions facilitate movement of the sperm as well as providing a physiological buffer against the acidic environment of the female tract. There is species variation in which glands are present:<br /> *Bull and stallion – Ampullary, vesicular, prostate and bulbourethral glands<br /> *Boar – Vesicular, prostate and bulbourethral glands<br /> *Tom Cat – Ampullary, prostate and bulbourethral glands<br /> *Dog – prostate glands only<br /> <br /> Development and function of the accessory sex glands is androgen dependant. This is highlighted by individuals producing little or no androgens having small accessory sex glands.<br /> <br /> ==Bulbourethral Glands==<br /> *Paired glands<br /> *Found near the ischial arch either side of the urethra<br /> *These are very dense glands containing a lot of fibrous connective tissue.<br /> *These glands are very large in the boar and absent in the dog.<br /> <br /> ==Prostate Gland==<br /> *Singular gland<br /> *Found at the junction between the bladder and the urethra.<br /> *Huge variation between species with regard to size and shape; heart shaped in the boar, h-shaped in the stallion and consists of four lobes in the tom. <br /> *It can consist of two different parts:<br /> **'''Corpus prostate''' – a compact body of tissue found external to the urethra. The stallion only possesses this part of the prostate gland and in the dog &amp; tom cat the corpus is very large and globular. This part is absent in the Ram and other small ruminants. The bull possesses both corpus and disseminate parts of the gland.<br /> **'''Disseminate prostate''' – a diffuse tissue found within the wall of the pelvic urethra. The prostate gland in the ram is entirely disseminate and in the boar makes up the major part of the gland. This part of the gland is absent in the stallion and vestigial in the dog and tom cat.<br /> <br /> ==Ampullary Glands==<br /> *Paired glands<br /> *Found lying on the dorsal neck of the bladder. They develop due to a glandular enlargement within the wall of the ductus deferens as it crosses the dorsal surface of the bladder. <br /> *The glands are connected to the urethra via the ejaculatory duct.<br /> <br /> ==Vesicular Glands==<br /> *Paired glands<br /> *Found dorsocranial to the pelvic urethra<br /> *In the boar and bull these glands produce a large proportion of the overall volume of ejaculate.<br /> *In the bull and boar these glands have irregular surface but in the stallion they are smooth.</div>

Amycartmel https://en.wikivet.net/index.php?title=Penis_-_Anatomy_%26_Physiology&diff=32423 2008-08-29T01:48:02Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> =The penis=<br /> ==Introduction==<br /> The penis is the male copulatory organ. It is formed from three parts; two Corpora cavernosa, comprising of cavernous tissue and a connective tissue sheath the tunica albuginea, and the single Corpus Spongiosum which contains the urethra encased in a vascular tissue sleeve. There are two types of penis: the musculovascular and fibroelastic penis.<br /> <br /> ==Structure==<br /> '''Corpus Cavernosum'''<br /> <br /> The corpus cavernosum is made up from the paired columns of cavernous tissue surrounded by connective tissue known as the crura of the penis or corpora cavernosa. <br /> *In the dog the distal corpus cavernosum is transformed into bone to form the [[Reproductive_Behaviour_-_Copulatory_Behaviour_Dog_-_Anatomy_%26_Physiology|Os penis]] which plays an important part in the dog achieving intromission with the bitch during copulation.<br /> <br /> '''Corpus spongiosum'''<br /> <br /> The corpus spongiosum is a vascular tissue sleeve surrounding the urethra. It commences at the bulb of the penis as an enlargement of the spongy tissue of the pelvic urethra. At the end of the penis the copus spongiosum expands over the distal end of the corpus cavernosum to form the '''Glans penis''', bringing the urethra to the extremity of the penis. There is a great variation in the morphology of the glans penis between species which often correspond to the female tract morphology. For example the boars “corkscrew” glans penis corresponds to the many interdigitating prominences of the sow’s cervix. The glans penis is highly populated with sensory nerves.<br /> <br /> '''Prepuce'''<br /> <br /> The prepuce is the skin sheath that conceals the penis when it is flaccid and is formed by an invagination of the abdominal skin. The prepuce is hairless and contains many smegma secreting glands important for lubrication between the shaft of the penis and the prepuce during copulation. Within the prepuce are varying amounts of striated muscle fibres; the cranial prepucial muscles responsible for retracting the prepuce and the caudal prepucial muscles responsible for protracting the prepuce.<br /> <br /> ==Glans Penis morphology==<br /> [[Image:Glans Penis Morphology.jpg|thumb|right|300px|Glans Penis Morphology - Copyright Amy Cartmel]]<br /> *Bull – slightly spiralled end<br /> *Boar – corkscrew shaped with a left hand thread<br /> *Ram – large extension of the urethral process<br /> *Stallion – Mushroom shaped with slight protrusion of the urethral process<br /> *Dog – substantial glans penis which is devided into the '''bulbus glandis''' found proximally and the '''pars longa glandis''' found distally<br /> *Tom cat – cone shaped with Keratinised Papillae, directed caudally<br /> <br /> ==Types of Penis==<br /> '''Fibroelastic'''<br /> <br /> Found in:<br /> *Bull, Boar, Ram, Deer<br /> *Contain large amounts of connective tissue and elastic fibres but limited erectile tissue.<br /> *Contain a sigmoid flexure <br /> *They are encased by a non-expandable connective tissue sheath called the tunica albuginea. Therefore, erection only results in increased length of penis and no increase in diameter of the penis. However, most of the increase in penile length is actually due to the straightening of the sigmoid flexure.<br /> * The cavernous tissue contains small blood spaces which means that only a small increase in blood to the penis is require to achieve erection.<br /> <br /> '''Musculovascular'''<br /> <br /> Found in:<br /> *Man, Stallion, Dog, Tom Cat<br /> *This penis structure contains a lot of erectile tissue and little connective tissue so during erection there is both an increase in length and diameter of the penis.<br /> *The cavernous tissue contains large blood spaces divided by thin septa. Therefore, a relatively larger volume of blood is required to achieve erection.<br /> <br /> ==Muscles associated with the penis==<br /> '''Bulbospongiosus'''<br /> *A single muscle that covers the root and ventral surface of the penis as well as the Bulbourethral glands (link to glands page)<br /> *The function of this muscle is to empty the extrapelvic urethra of sperm in a similar way to the Urethralis muscle emptying the pelvic urethra.<br /> <br /> '''Ischiocavernosus Muscles'''<br /> *Paired muscles located at the root of the penis.<br /> *Connect the penis to the ischial arch of the pelvis.<br /> <br /> '''Retractor penis Muscles'''<br /> *Paired muscles oringinating on the caudal vertebrae and inserting on the ventrolateral surfaces of the penis.<br /> *Maintains the sigmoid flexure of the fibroelastic penis when the muscles are contracted.<br /> *When the muscles are relaxed the penis protrudes through the prepuce as the sigmoid flexure unbends.<br /> <br /> ==Vasculature==<br /> The artery of the penis is a direct branch off the internal pudendal artery. It splits into three branches:<br /> *Artery of the bulb – supplies the corpus spongiosus<br /> *Deep artery of the penis – supplies the corpus cavernosum <br /> *Dorsal artery of the penis – supplies the glans penis<br /> The prepuce covering the flaccid penis is supplied by anastamosis between the external pudendal artery and the artery of the penis.<br /> <br /> ==Innervation==<br /> *Mostly parasympathetic from the paired pudendal nerves<br /> *The glans penis and internal lamina of the prepuce are heavily infiltrated by sensory nerve endings responsible for stimulating ejaculation (link to ejaculation)<br /> <br /> ==Lymphatics==<br /> Lymph from the penis and prepuce drains into the superficial inguinal lymph nodes.</div>

Amycartmel https://en.wikivet.net/index.php?title=Spermatogenesis_and_Spermiation_-_Anatomy_%26_Physiology&diff=32422 2008-08-29T01:39:11Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> [[Image:spermatogenesis.jpg|thumb|right|150px|Spermatogenesis Copyright Amy Cartmel 2008]]</div>

Amycartmel https://en.wikivet.net/index.php?title=File:Spermatogenesis.jpg&diff=32421 2008-08-29T01:37:13Z

<p>Amycartmel: </p> <hr /> <div></div>

Amycartmel https://en.wikivet.net/index.php?title=Spermatogenesis_and_Spermiation_-_Anatomy_%26_Physiology&diff=32420 2008-08-29T01:37:00Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> [[Image:spermatogenesis.jpg]]</div>

Amycartmel https://en.wikivet.net/index.php?title=Penis_-_Anatomy_%26_Physiology&diff=32418 2008-08-28T21:19:16Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> [[Image:Glans Penis Morphology.jpg|thumb|right|300px|Glans Penis Morphology - Copyright Amy Cartmel]]</div>

Amycartmel https://en.wikivet.net/index.php?title=File:Glans_Penis_Morphology.jpg&diff=32417 2008-08-28T21:17:25Z

<p>Amycartmel: </p> <hr /> <div></div>

Amycartmel https://en.wikivet.net/index.php?title=Penis_-_Anatomy_%26_Physiology&diff=32416 2008-08-28T21:17:13Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> [[Image:Glans Penis Morphology.jpg]]</div>

Amycartmel https://en.wikivet.net/index.php?title=Penis_-_Anatomy_%26_Physiology&diff=32415 2008-08-28T21:13:33Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> =Introduction=<br /> <br /> <br /> <br /> =Penis Structure=<br /> [[Image: Glans Penis Morphology| Glans Penis Morphology]]<br /> ==Musculovascular Penis==<br /> Found in:<br /> *Man<br /> *Stallion<br /> *Dog<br /> *Tom Cat<br /> This penis structure contains alot of erectile tissue and little connective tissue so at erection there is both an increase in length and diameter of the of the penis.<br /> <br /> ==Fibroelastic Penis==<br /> Found in:<br /> *Bull<br /> *Boar<br /> *Ram<br /> *Deer<br /> These have limited erectile tissue but many fibrous cross bonds and ar encased within a non-expandable connective tissue band the Tunica Albuginea.<br /> <br /> ==Glans Penis Appearance==</div>

Amycartmel https://en.wikivet.net/index.php?title=Penis_-_Anatomy_%26_Physiology&diff=32414 2008-08-28T21:03:11Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> =Introduction=<br /> <br /> <br /> <br /> =Penis Structure=<br /> [[Image: wiki penis pic| Glans Penis Morphology]]<br /> ==Musculovascular Penis==<br /> Found in:<br /> *Man<br /> *Stallion<br /> *Dog<br /> *Tom Cat<br /> This penis structure contains alot of erectile tissue and little connective tissue so at erection there is both an increase in length and diameter of the of the penis.<br /> <br /> ==Fibroelastic Penis==<br /> Found in:<br /> *Bull<br /> *Boar<br /> *Ram<br /> *Deer<br /> These have limited erectile tissue but many fibrous cross bonds and ar encased within a non-expandable connective tissue band the Tunica Albuginea.<br /> <br /> ==Glans Penis Appearance==</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=27424 2008-08-13T19:31:39Z

<p>Amycartmel: /* Histology */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> =The Testes=<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> '''Scrotum '''<br /> *Skin - Contains many sweat glands, thermosensitive receptors and sympathetic nerves.<br /> *Tunica Dartos - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures, as it can maintain sustained contraction, and letting the testes lower in hot weather, increasing the surface area for heat loss from the skin.<br /> *Scrotal fascia<br /> *Parietal Vaginal Tunic - The first peritoneam layer taken into the scrotum by the peritoneum fusion with the gubernaculum during testicular descent.<br /> '''Vaginal Cavity''' - A potential space<br /> <br /> '''Testicular Capsule'''<br /> *Visceral Vaginal Tunic - The second peritoneum layer within the scrotum. This layer is closely applied to the Tunica Albuginea.<br /> *Tunica Albuginea - A connective tissue layer containing some smooth muscle fibres. The Tunica Albuginea sends projections from the capsules into the testicular parenchyma that join up with the mediastinum of the testis forming lobules. Contraction and relaxation of the smooth muscle fibres within the Tunica Albuginea in response to Acetylcholine and Norepinephrine results in a pumping action facilitating the flow of spermatozoa through the tubules of the testes.<br /> '''Testicular Parenchyma'''<br /> *Interstitial Leydig cells - Produce the androgen testosterone important for supporting spermatogenesis.<br /> *Cappilaries, Lymphatic vessels, connective tissue.<br /> '''Tubular Compartment'''<br /> *Seminipherous Tubules - Make up highly convoluted tubule network within the teste parenchyma. These seminipherous tubules connect to Rete tubules. The Seminipherous epithelium making up the tubules can be devided into two compartments seperated by junctional complexes between the somatic Sertoli cells within the epithelium:<br /> **Basal Compartment - containing spermatogonia, proliferating germ cells.<br /> **Adluminal Compartment - Containing Spermatocytes, Spermatids and spermatozoa<br /> The Sertoli cells are much larger than the developing germ cells and span the basement membrane to the lumen of the seminipherous tubules. Their function is provide support to developing germ cells and form the Blood-testis barrier. Each sertoli cells can only support a maximum number of developing germ cells. Therefore, the number of sertoli cells within a testis determine the sperm production capabilities of that individual.<br /> *Peritubular cells - contractile cells surrounding the seminipherous tubules<br /> <br /> ==Comparative Testicular Architecture==<br /> There are species differences between Sertoli cell number and parenchyma composition. In the Boar the parenchyma is made up from many Leydig cells and little lymph space, humans and Rams contain slighly more lymph space and the rat parenchyma is mainly lymph space with few leydig cells.<br /> <br /> ==Function==<br /> '''Scrotum'''<br /> *Temperature sensor<br /> *Protection<br /> *Cooling of testes - evaporative heat loss due to lots of sweat produced by glands in the skin.<br /> <br /> '''Seminipherous Tubules'''<br /> *Production of spermatozoa by Sertoli cells<br /> *Production of hormones by intersticial Leydig cells<br /> *The Blood-Testes Barrier formed by tight junctions between neighbouring Sertoli cells. This barrier prevents White blood cells from entering the adluminal compartment of the seminipherous tubules and autoreacting to the haploid spermatids within it.<br /> <br /> ==Histology==<br /> [[Image:Mature dog testis.jpg|thumb|right|150px|Mature Testis (Dog) - Copyright RVC 2008]]<br /> [[Image:Seminipherous Tubule.jpg|thumb|right|150px|Seminipherous Tubule (Dog) - Copyright RVC 2008]]<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.<br /> <br /> =The Epididymis=<br /> ==Introduction==<br /> The Epididymis provides the environment for final maturation of spermatozoa. It is here that they aquire motility and fertility. The Epididymal duct is very long, between 30-60 meters. It is devided functionally into 3 regions; the Caput (head), Corpus (body) and Cauda (tail). The caput of the epididymis is connected to the efferent ducts of the testes. The Cauda connects to the Ductus Deferens of the spermatic cord.<br /> <br /> ==Structure &amp; Function==<br /> '''Caput (head)'''<br /> *Fluid secreted in the rete tubules of the testes is reabsorbed here and epididymal fluid is secreted. This fluid secretion is important in order to facilitate movement of the sperm through the epididymis.<br /> '''Corpus (body)'''<br /> *Nuclear chromatin condenses via the addition of di-sulphide bridges. This condensation stabilises the nuclear material and can be observed histologically as darker staining material.<br /> *Stabilising surface proteins are added to the sperm membranes.<br /> *Sperm aquire fertility by the addition of membrane receptors to female tract ligands. This enables them to bind to the [[Zona Pellucida]] and oocyte membranes.<br /> *Sperm cells are dehydrated.<br /> *Sperm aquire forward motility.<br /> '''Cauda (tail)'''<br /> *Sperm metabolic activity is depressed in order to prolong life.<br /> *Sperm are stored here until ejaculation.<br /> <br /> ==Histology==<br /> The Epididymal duct is surrounded by smooth muscle fibers. These fibers contract rhythmically facilitating sperm movement through the duct.<br /> <br /> '''Caput'''<br /> *Columna epithelium with basal nuclei.<br /> *Small steriocillia present, these have an absorbtive function<br /> '''Corpus'''<br /> *Low columna epithelium with very prominant stereocillia.<br /> *Small groups of sperm can be observed within the lumen of the duct.<br /> '''Cauda'''<br /> *Cuboidal/ Low columna epithelium. However, unlike the caput and corpus regions of the epididymis the cauda epithelium has no stereocillia.<br /> *Large numbers of sperm observable here as this is the site of sperm storage within the testes.</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=27423 2008-08-13T19:31:18Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> =The Testes=<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> '''Scrotum '''<br /> *Skin - Contains many sweat glands, thermosensitive receptors and sympathetic nerves.<br /> *Tunica Dartos - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures, as it can maintain sustained contraction, and letting the testes lower in hot weather, increasing the surface area for heat loss from the skin.<br /> *Scrotal fascia<br /> *Parietal Vaginal Tunic - The first peritoneam layer taken into the scrotum by the peritoneum fusion with the gubernaculum during testicular descent.<br /> '''Vaginal Cavity''' - A potential space<br /> <br /> '''Testicular Capsule'''<br /> *Visceral Vaginal Tunic - The second peritoneum layer within the scrotum. This layer is closely applied to the Tunica Albuginea.<br /> *Tunica Albuginea - A connective tissue layer containing some smooth muscle fibres. The Tunica Albuginea sends projections from the capsules into the testicular parenchyma that join up with the mediastinum of the testis forming lobules. Contraction and relaxation of the smooth muscle fibres within the Tunica Albuginea in response to Acetylcholine and Norepinephrine results in a pumping action facilitating the flow of spermatozoa through the tubules of the testes.<br /> '''Testicular Parenchyma'''<br /> *Interstitial Leydig cells - Produce the androgen testosterone important for supporting spermatogenesis.<br /> *Cappilaries, Lymphatic vessels, connective tissue.<br /> '''Tubular Compartment'''<br /> *Seminipherous Tubules - Make up highly convoluted tubule network within the teste parenchyma. These seminipherous tubules connect to Rete tubules. The Seminipherous epithelium making up the tubules can be devided into two compartments seperated by junctional complexes between the somatic Sertoli cells within the epithelium:<br /> **Basal Compartment - containing spermatogonia, proliferating germ cells.<br /> **Adluminal Compartment - Containing Spermatocytes, Spermatids and spermatozoa<br /> The Sertoli cells are much larger than the developing germ cells and span the basement membrane to the lumen of the seminipherous tubules. Their function is provide support to developing germ cells and form the Blood-testis barrier. Each sertoli cells can only support a maximum number of developing germ cells. Therefore, the number of sertoli cells within a testis determine the sperm production capabilities of that individual.<br /> *Peritubular cells - contractile cells surrounding the seminipherous tubules<br /> <br /> ==Comparative Testicular Architecture==<br /> There are species differences between Sertoli cell number and parenchyma composition. In the Boar the parenchyma is made up from many Leydig cells and little lymph space, humans and Rams contain slighly more lymph space and the rat parenchyma is mainly lymph space with few leydig cells.<br /> <br /> ==Function==<br /> '''Scrotum'''<br /> *Temperature sensor<br /> *Protection<br /> *Cooling of testes - evaporative heat loss due to lots of sweat produced by glands in the skin.<br /> <br /> '''Seminipherous Tubules'''<br /> *Production of spermatozoa by Sertoli cells<br /> *Production of hormones by intersticial Leydig cells<br /> *The Blood-Testes Barrier formed by tight junctions between neighbouring Sertoli cells. This barrier prevents White blood cells from entering the adluminal compartment of the seminipherous tubules and autoreacting to the haploid spermatids within it.<br /> <br /> ==Histology==<br /> [[Image:Mature dog testis.jpg|thumb|right|150px|Mature Testis (Dog) - Copyright RVC 2008]]<br /> [[Image:Seminipherous Tubule.jpg|thumb|right|150px|Seminipherous Tubule (Dog) - Copyright RVC 2008]]<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.<br /> <br /> =The Epididymis=<br /> ==Introduction==<br /> The Epididymis provides the environment for final maturation of spermatozoa. It is here that they aquire motility and fertility. The Epididymal duct is very long, between 30-60 meters. It is devided functionally into 3 regions; the Caput (head), Corpus (body) and Cauda (tail). The caput of the epididymis is connected to the efferent ducts of the testes. The Cauda connects to the Ductus Deferens of the spermatic cord.<br /> <br /> ==Structure &amp; Function==<br /> '''Caput (head)'''<br /> *Fluid secreted in the rete tubules of the testes is reabsorbed here and epididymal fluid is secreted. This fluid secretion is important in order to facilitate movement of the sperm through the epididymis.<br /> '''Corpus (body)'''<br /> *Nuclear chromatin condenses via the addition of di-sulphide bridges. This condensation stabilises the nuclear material and can be observed histologically as darker staining material.<br /> *Stabilising surface proteins are added to the sperm membranes.<br /> *Sperm aquire fertility by the addition of membrane receptors to female tract ligands. This enables them to bind to the [[Zona Pellucida]] and oocyte membranes.<br /> *Sperm cells are dehydrated.<br /> *Sperm aquire forward motility.<br /> '''Cauda (tail)'''<br /> *Sperm metabolic activity is depressed in order to prolong life.<br /> *Sperm are stored here until ejaculation.<br /> <br /> ==Histology==<br /> The Epididymal duct is surrounded by smooth muscle fibers. These fibers contract rhythmically facilitating sperm movement through the duct.<br /> '''Caput'''<br /> *Columna epithelium with basal nuclei.<br /> *Small steriocillia present, these have an absorbtive function<br /> '''Corpus'''<br /> *Low columna epithelium with very prominant stereocillia.<br /> *Small groups of sperm can be observed within the lumen of the duct.<br /> '''Cauda'''<br /> *Cuboidal/ Low columna epithelium. However, unlike the caput and corpus regions of the epididymis the cauda epithelium has no stereocillia.<br /> *Large numbers of sperm observable here as this is the site of sperm storage within the testes.</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=27257 2008-08-13T11:57:07Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> =The Testes=<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> '''Scrotum '''<br /> *Skin - Contains many sweat glands, thermosensitive receptors and sympathetic nerves.<br /> *Tunica Dartos - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures, as it can maintain sustained contraction, and letting the testes lower in hot weather, increasing the surface area for heat loss from the skin.<br /> *Scrotal fascia<br /> *Parietal Vaginal Tunic - The first peritoneam layer taken into the scrotum by the peritoneum fusion with the gubernaculum during testicular descent.<br /> '''Vaginal Cavity''' - A potential space<br /> <br /> '''Testicular Capsule'''<br /> *Visceral Vaginal Tunic - The second peritoneum layer within the scrotum. This layer is closely applied to the Tunica Albuginea.<br /> *Tunica Albuginea - A connective tissue layer containing some smooth muscle fibres. The Tunica Albuginea sends projections from the capsules into the testicular parenchyma that join up with the mediastinum of the testis forming lobules. Contraction and relaxation of the smooth muscle fibres within the Tunica Albuginea in response to Acetylcholine and Norepinephrine results in a pumping action facilitating the flow of spermatozoa through the tubules of the testes.<br /> '''Testicular Parenchyma'''<br /> *Interstitial Leydig cells - Produce the androgen testosterone important for supporting spermatogenesis.<br /> *Cappilaries, Lymphatic vessels, connective tissue.<br /> '''Tubular Compartment'''<br /> *Seminipherous Tubules - Make up highly convoluted tubule network within the teste parenchyma. These seminipherous tubules connect to Rete tubules. The Seminipherous epithelium making up the tubules can be devided into two compartments seperated by junctional complexes between the somatic Sertoli cells within the epithelium:<br /> **Basal Compartment - containing spermatogonia, proliferating germ cells.<br /> **Adluminal Compartment - Containing Spermatocytes, Spermatids and spermatozoa<br /> The Sertoli cells are much larger than the developing germ cells and span the basement membrane to the lumen of the seminipherous tubules. Their function is provide support to developing germ cells and form the Blood-testis barrier. Each sertoli cells can only support a maximum number of developing germ cells. Therefore, the number of sertoli cells within a testis determine the sperm production capabilities of that individual.<br /> *Peritubular cells - contractile cells surrounding the seminipherous tubules<br /> <br /> ==Comparative Testicular Architecture==<br /> There are species differences between Sertoli cell number and parenchyma composition. In the Boar the parenchyma is made up from many Leydig cells and little lymph space, humans and Rams contain slighly more lymph space and the rat parenchyma is mainly lymph space with few leydig cells.<br /> <br /> ==Function==<br /> '''Scrotum'''<br /> *Temperature sensor<br /> *Protection<br /> *Cooling of testes - evaporative heat loss due to lots of sweat produced by glands in the skin.<br /> <br /> '''Seminipherous Tubules'''<br /> *Production of spermatozoa by Sertoli cells<br /> *Production of hormones by intersticial Leydig cells<br /> *The Blood-Testes Barrier formed by tight junctions between neighbouring Sertoli cells. This barrier prevents White blood cells from entering the adluminal compartment of the seminipherous tubules and autoreacting to the haploid spermatids within it.<br /> <br /> ==Histology==<br /> [[Image:Mature dog testis.jpg|thumb|right|150px|Mature Testis (Dog) - Copyright RVC 2008]]<br /> [[Image:Seminipherous Tubule.jpg|thumb|right|150px|Seminipherous Tubule (Dog) - Copyright RVC 2008]]<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.<br /> <br /> =The Epididymis=<br /> ==Introduction==<br /> <br /> ==Structure &amp; Function==<br /> <br /> ==Histology==</div>

Amycartmel https://en.wikivet.net/index.php?title=Penis_-_Anatomy_%26_Physiology&diff=26705 2008-08-11T11:13:12Z

<p>Amycartmel: /* Fibroelastic Penis */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> =Introduction=<br /> <br /> <br /> <br /> =Penis Structure=<br /> <br /> ==Musculovascular Penis==<br /> Found in:<br /> *Man<br /> *Stallion<br /> *Dog<br /> *Tom Cat<br /> This penis structure contains alot of erectile tissue and little connective tissue so at erection there is both an increase in length and diameter of the of the penis.<br /> <br /> ==Fibroelastic Penis==<br /> Found in:<br /> *Bull<br /> *Boar<br /> *Ram<br /> *Deer<br /> These have limited erectile tissue but many fibrous cross bonds and ar encased within a non-expandable connective tissue band the Tunica Albuginea.<br /> <br /> ==Glans Penis Appearance==</div>

Amycartmel https://en.wikivet.net/index.php?title=Penis_-_Anatomy_%26_Physiology&diff=26701 2008-08-11T11:05:03Z

<p>Amycartmel: /* Musculovascular Penis */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> =Introduction=<br /> <br /> <br /> <br /> =Penis Structure=<br /> <br /> ==Musculovascular Penis==<br /> Found in:<br /> *Man<br /> *Stallion<br /> *Dog<br /> *Tom Cat<br /> This penis structure contains alot of erectile tissue and little connective tissue so at erection there is both an increase in length and diameter of the of the penis.<br /> <br /> ==Fibroelastic Penis==<br /> <br /> ==Glans Penis Appearance==</div>

Amycartmel https://en.wikivet.net/index.php?title=Penis_-_Anatomy_%26_Physiology&diff=26700 2008-08-11T11:02:10Z

<p>Amycartmel: /* Musculovascular Penis */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> =Introduction=<br /> <br /> <br /> <br /> =Penis Structure=<br /> <br /> ==Musculovascular Penis==<br /> Found in:<br /> *Man<br /> *Stallion<br /> *Dog<br /> *Tom Cat<br /> this penis structure contains alot of<br /> <br /> ==Fibroelastic Penis==<br /> <br /> ==Glans Penis Appearance==</div>

Amycartmel https://en.wikivet.net/index.php?title=Penis_-_Anatomy_%26_Physiology&diff=26694 2008-08-11T10:45:06Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> =Introduction=<br /> <br /> <br /> <br /> =Penis Structure=<br /> <br /> ==Musculovascular Penis==<br /> <br /> ==Fibroelastic Penis==<br /> <br /> ==Glans Penis Appearance==</div>

Amycartmel https://en.wikivet.net/index.php?title=Penis_-_Anatomy_%26_Physiology&diff=26693 2008-08-11T10:44:00Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> ==Introduction==<br /> <br /> <br /> <br /> ==Penis Structure==<br /> <br /> =Musculovascular Penis=<br /> <br /> =Fibroelastic Penis=<br /> <br /> =Glans Penis Appearance=</div>

Amycartmel https://en.wikivet.net/index.php?title=Penis_-_Anatomy_%26_Physiology&diff=26692 2008-08-11T10:40:30Z

<p>Amycartmel: /* External Genitalia development */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> ==Introduction==<br /> <br /> <br /> <br /> ==Penis Structure==</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26691 2008-08-11T10:39:03Z

<p>Amycartmel: /* Testicular Architecture */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> '''Scrotum '''<br /> *Skin - Contains many sweat glands, thermosensitive receptors and sympathetic nerves.<br /> *Tunica Dartos - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures, as it can maintain sustained contraction, and letting the testes lower in hot weather, increasing the surface area for heat loss from the skin.<br /> *Scrotal fascia<br /> *Parietal Vaginal Tunic - The first peritoneam layer taken into the scrotum by the peritoneum fusion with the gubernaculum during testicular descent.<br /> '''Vaginal Cavity''' - A potential space<br /> <br /> '''Testicular Capsule'''<br /> *Visceral Vaginal Tunic - The second peritoneum layer within the scrotum. This layer is closely applied to the Tunica Albuginea.<br /> *Tunica Albuginea - A connective tissue layer containing some smooth muscle fibres. The Tunica Albuginea sends projections from the capsules into the testicular parenchyma that join up with the mediastinum of the testis forming lobules. Contraction and relaxation of the smooth muscle fibres within the Tunica Albuginea in response to Acetylcholine and Norepinephrine results in a pumping action facilitating the flow of spermatozoa through the tubules of the testes.<br /> '''Testicular Parenchyma'''<br /> *Interstitial Leydig cells - Produce the androgen testosterone important for supporting spermatogenesis.<br /> *Cappilaries, Lymphatic vessels, connective tissue.<br /> '''Tubular Compartment'''<br /> *Seminipherous Tubules - Make up highly convoluted tubule network within the teste parenchyma. These seminipherous tubules connect to Rete tubules. The Seminipherous epithelium making up the tubules can be devided into two compartments seperated by junctional complexes between the somatic Sertoli cells within the epithelium:<br /> **Basal Compartment - containing spermatogonia, proliferating germ cells.<br /> **Adluminal Compartment - Containing Spermatocytes, Spermatids and spermatozoa<br /> The Sertoli cells are much larger than the developing germ cells and span the basement membrane to the lumen of the seminipherous tubules. Their function is provide support to developing germ cells and form the Blood-testis barrier. Each sertoli cells can only support a maximum number of developing germ cells. Therefore, the number of sertoli cells within a testis determine the sperm production capabilities of that individual.<br /> *Peritubular cells - contractile cells surrounding the seminipherous tubules<br /> <br /> ==Comparative Testicular Architecture==<br /> There are species differences between Sertoli cell number and parenchyma composition. In the Boar the parenchyma is made up from many Leydig cells and little lymph space, humans and Rams contain slighly more lymph space and the rat parenchyma is mainly lymph space with few leydig cells.<br /> <br /> ==Function==<br /> '''Scrotum'''<br /> *Temperature sensor<br /> *Protection<br /> *Cooling of testes - evaporative heat loss due to lots of sweat produced by glands in the skin.<br /> <br /> '''Seminipherous Tubules'''<br /> *Production of spermatozoa by Sertoli cells<br /> *Production of hormones by intersticial Leydig cells<br /> *The Blood-Testes Barrier formed by tight junctions between neighbouring Sertoli cells. This barrier prevents White blood cells from entering the adluminal compartment of the seminipherous tubules and autoreacting to the haploid spermatids within it.<br /> <br /> ==Histology==<br /> [[Image:Mature dog testis.jpg|thumb|right|150px|Mature Testis (Dog) - Copyright RVC 2008]]<br /> [[Image:Seminipherous Tubule.jpg|thumb|right|150px|Seminipherous Tubule (Dog) - Copyright RVC 2008]]<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26690 2008-08-11T10:38:43Z

<p>Amycartmel: /* Testicular Architecture */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> '''Scrotum '''<br /> *Skin - Contains many sweat glands, thermosensitive receptors and sympathetic nerves.<br /> *Tunica Dartos - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures, as it can maintain sustained contraction, and letting the testes lower in hot weather, increasing the surface area for heat loss from the skin.<br /> *Scrotal fascia<br /> *Parietal Vaginal Tunic - The first peritoneam layer taken into the scrotum by the peritoneum fusion with the gubernaculum during testicular descent.<br /> '''Vaginal Cavity''' - A potential space<br /> '''Testicular Capsule'''<br /> *Visceral Vaginal Tunic - The second peritoneum layer within the scrotum. This layer is closely applied to the Tunica Albuginea.<br /> *Tunica Albuginea - A connective tissue layer containing some smooth muscle fibres. The Tunica Albuginea sends projections from the capsules into the testicular parenchyma that join up with the mediastinum of the testis forming lobules. Contraction and relaxation of the smooth muscle fibres within the Tunica Albuginea in response to Acetylcholine and Norepinephrine results in a pumping action facilitating the flow of spermatozoa through the tubules of the testes.<br /> '''Testicular Parenchyma'''<br /> *Interstitial Leydig cells - Produce the androgen testosterone important for supporting spermatogenesis.<br /> *Cappilaries, Lymphatic vessels, connective tissue.<br /> '''Tubular Compartment'''<br /> *Seminipherous Tubules - Make up highly convoluted tubule network within the teste parenchyma. These seminipherous tubules connect to Rete tubules. The Seminipherous epithelium making up the tubules can be devided into two compartments seperated by junctional complexes between the somatic Sertoli cells within the epithelium:<br /> **Basal Compartment - containing spermatogonia, proliferating germ cells.<br /> **Adluminal Compartment - Containing Spermatocytes, Spermatids and spermatozoa<br /> The Sertoli cells are much larger than the developing germ cells and span the basement membrane to the lumen of the seminipherous tubules. Their function is provide support to developing germ cells and form the Blood-testis barrier. Each sertoli cells can only support a maximum number of developing germ cells. Therefore, the number of sertoli cells within a testis determine the sperm production capabilities of that individual.<br /> *Peritubular cells - contractile cells surrounding the seminipherous tubules<br /> <br /> ==Comparative Testicular Architecture==<br /> There are species differences between Sertoli cell number and parenchyma composition. In the Boar the parenchyma is made up from many Leydig cells and little lymph space, humans and Rams contain slighly more lymph space and the rat parenchyma is mainly lymph space with few leydig cells.<br /> <br /> ==Function==<br /> '''Scrotum'''<br /> *Temperature sensor<br /> *Protection<br /> *Cooling of testes - evaporative heat loss due to lots of sweat produced by glands in the skin.<br /> <br /> '''Seminipherous Tubules'''<br /> *Production of spermatozoa by Sertoli cells<br /> *Production of hormones by intersticial Leydig cells<br /> *The Blood-Testes Barrier formed by tight junctions between neighbouring Sertoli cells. This barrier prevents White blood cells from entering the adluminal compartment of the seminipherous tubules and autoreacting to the haploid spermatids within it.<br /> <br /> ==Histology==<br /> [[Image:Mature dog testis.jpg|thumb|right|150px|Mature Testis (Dog) - Copyright RVC 2008]]<br /> [[Image:Seminipherous Tubule.jpg|thumb|right|150px|Seminipherous Tubule (Dog) - Copyright RVC 2008]]<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26689 2008-08-11T10:37:30Z

<p>Amycartmel: /* Testicular Architecture */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> *'''Scrotum '''<br /> **Skin - Contains many sweat glands, thermosensitive receptors and sympathetic nerves.<br /> **Tunica Dartos - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures, as it can maintain sustained contraction, and letting the testes lower in hot weather, increasing the surface area for heat loss from the skin.<br /> **Scrotal fascia<br /> **Parietal Vaginal Tunic - The first peritoneam layer taken into the scrotum by the peritoneum fusion with the gubernaculum during testicular descent.<br /> *'''Vaginal Cavity''' - A potential space<br /> *'''Testicular Capsule'''<br /> **Visceral Vaginal Tunic - The second peritoneum layer within the scrotum. This layer is closely applied to the Tunica Albuginea.<br /> **Tunica Albuginea - A connective tissue layer containing some smooth muscle fibres. The Tunica Albuginea sends projections from the capsules into the testicular parenchyma that join up with the mediastinum of the testis forming lobules. Contraction and relaxation of the smooth muscle fibres within the Tunica Albuginea in response to Acetylcholine and Norepinephrine results in a pumping action facilitating the flow of spermatozoa through the tubules of the testes.<br /> *'''Testicular Parenchyma'''<br /> **Interstitial Leydig cells - Produce the androgen testosterone important for supporting spermatogenesis.<br /> **Cappilaries, Lymphatic vessels, connective tissue.<br /> *'''Tubular Compartment'''<br /> **Seminipherous Tubules - Make up highly convoluted tubule network within the teste parenchyma. These seminipherous tubules connect to Rete tubules. The Seminipherous epithelium making up the tubules can be devided into two compartments seperated by junctional complexes between the somatic Sertoli cells within the epithelium:<br /> ***Basal Compartment - containing spermatogonia, proliferating germ cells.<br /> ***Adluminal Compartment - Containing Spermatocytes, Spermatids and spermatozoa<br /> The Sertoli cells are much larger than the developing germ cells and span the basement membrane to the lumen of the seminipherous tubules. Their function is provide support to developing germ cells and form the Blood-testis barrier. Each sertoli cells can only support a maximum number of developing germ cells. Therefore, the number of sertoli cells within a testis determine the sperm production capabilities of that individual.<br /> **Peritubular cells - contractile cells surrounding the seminipherous tubules<br /> <br /> ==Comparative Testicular Architecture==<br /> There are species differences between Sertoli cell number and parenchyma composition. In the Boar the parenchyma is made up from many Leydig cells and little lymph space, humans and Rams contain slighly more lymph space and the rat parenchyma is mainly lymph space with few leydig cells.<br /> <br /> ==Function==<br /> '''Scrotum'''<br /> *Temperature sensor<br /> *Protection<br /> *Cooling of testes - evaporative heat loss due to lots of sweat produced by glands in the skin.<br /> <br /> '''Seminipherous Tubules'''<br /> *Production of spermatozoa by Sertoli cells<br /> *Production of hormones by intersticial Leydig cells<br /> *The Blood-Testes Barrier formed by tight junctions between neighbouring Sertoli cells. This barrier prevents White blood cells from entering the adluminal compartment of the seminipherous tubules and autoreacting to the haploid spermatids within it.<br /> <br /> ==Histology==<br /> [[Image:Mature dog testis.jpg|thumb|right|150px|Mature Testis (Dog) - Copyright RVC 2008]]<br /> [[Image:Seminipherous Tubule.jpg|thumb|right|150px|Seminipherous Tubule (Dog) - Copyright RVC 2008]]<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26688 2008-08-11T10:37:10Z

<p>Amycartmel: /* Testicular Architecture */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> *'''Scrotum '''<br /> **Skin - Contains many sweat glands, thermosensitive receptors and sympathetic nerves.<br /> **Tunica Dartos - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures, as it can maintain sustained contraction, and letting the testes lower in hot weather, increasing the surface area for heat loss from the skin.<br /> **Scrotal fascia<br /> **Parietal Vaginal Tunic - The first peritoneam layer taken into the scrotum by the peritoneum fusion with the gubernaculum during testicular descent.<br /> *'''Vaginal Cavity''' - A potential space<br /> *'''Testicular Capsule'''<br /> **Visceral Vaginal Tunic - The second peritoneum layer within the scrotum. This layer is closely applied to the Tunica Albuginea.<br /> **Tunica Albuginea - A connective tissue layer containing some smooth muscle fibres. The Tunica Albuginea sends projections from the capsules into the testicular parenchyma that join up with the mediastinum of the testis forming lobules. Contraction and relaxation of the smooth muscle fibres within the Tunica Albuginea in response to Acetylcholine and Norepinephrine results in a pumping action facilitating the flow of spermatozoa through the tubules of the testes.<br /> *'''Testicular Parenchyma'''<br /> **Interstitial Leydig cells - Produce the androgen testosterone important for supporting spermatogenesis.<br /> **Cappilaries, Lymphatic vessels, connective tissue.<br /> *'''Tubular Compartment'''<br /> **Seminipherous Tubules - Make up highly convoluted tubule network within the teste parenchyma. These seminipherous tubules connect to Rete tubules. The Seminipherous epithelium making up the tubules can be devided into two compartments seperated by junctional complexes between the somatic Sertoli cells within the epithelium:<br /> ***Basal Compartment - containing spermatogonia, proliferating germ cells.<br /> ***Adluminal Compartment - Containing Spermatocytes, Spermatids and spermatozoa<br /> The Sertoli cells are much larger than the developing germ cells and span the basement membrane to the lumen of the seminipherous tubules. Their function is provide support to developing germ cells and form the Blood-testis barrier. Each sertoli cells can only support a maximum number of developing germ cells. Therefore, the number of sertoli cells within a testis determine the sperm production capabilities of that individual.<br /> **peritubular cells - contractile cells surrounding the seminipherous tubules<br /> <br /> ==Comparative Testicular Architecture==<br /> There are species differences between Sertoli cell number and parenchyma composition. In the Boar the parenchyma is made up from many Leydig cells and little lymph space, humans and Rams contain slighly more lymph space and the rat parenchyma is mainly lymph space with few leydig cells.<br /> <br /> ==Function==<br /> '''Scrotum'''<br /> *Temperature sensor<br /> *Protection<br /> *Cooling of testes - evaporative heat loss due to lots of sweat produced by glands in the skin.<br /> <br /> '''Seminipherous Tubules'''<br /> *Production of spermatozoa by Sertoli cells<br /> *Production of hormones by intersticial Leydig cells<br /> *The Blood-Testes Barrier formed by tight junctions between neighbouring Sertoli cells. This barrier prevents White blood cells from entering the adluminal compartment of the seminipherous tubules and autoreacting to the haploid spermatids within it.<br /> <br /> ==Histology==<br /> [[Image:Mature dog testis.jpg|thumb|right|150px|Mature Testis (Dog) - Copyright RVC 2008]]<br /> [[Image:Seminipherous Tubule.jpg|thumb|right|150px|Seminipherous Tubule (Dog) - Copyright RVC 2008]]<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26687 2008-08-11T10:36:43Z

<p>Amycartmel: /* Testicular Architecture */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> *'''Scrotum '''<br /> **Skin - Contains many sweat glands, thermosensitive receptors and sympathetic nerves.<br /> **Tunica Dartos - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures, as it can maintain sustained contraction, and letting the testes lower in hot weather, increasing the surface area for heat loss from the skin.<br /> **Scrotal fascia<br /> **Parietal Vaginal Tunic - The first peritoneam layer taken into the scrotum by the peritoneum fusion with the gubernaculum during testicular descent.<br /> *'''Vaginal Cavity''' - A potential space<br /> *'''Testicular Capsule'''<br /> **Visceral Vaginal Tunic - The second peritoneum layer within the scrotum. This layer is closely applied to the Tunica Albuginea.<br /> **Tunica Albuginea - A connective tissue layer containing some smooth muscle fibres. The Tunica Albuginea sends projections from the capsules into the testicular parenchyma that join up with the mediastinum of the testis forming lobules. Contraction and relaxation of the smooth muscle fibres within the Tunica Albuginea in response to Acetylcholine and Norepinephrine results in a pumping action facilitating the flow of spermatozoa through the tubules of the testes.<br /> *'''Testicular Parenchyma'''<br /> **Interstitial Leydig cells - Produce the androgen testosterone important for supporting spermatogenesis.<br /> **Cappilaries, Lymphatic vessels, connective tissue.<br /> *'''Tubular Compartment'''<br /> **Seminipherous Tubules - Make up highly convoluted tubule network within the teste parenchyma. These seminipherous tubules connect to Rete tubules. The Seminipherous epithelium making up the tubules can be devided into two compartments seperated by junctional complexes between the somatic Sertoli cells within the epithelium:<br /> ***Basal Compartment - containing spermatogonia, proliferating germ cells.<br /> ***Adluminal Compartment - Containing Spermatocytes, Spermatids and spermatozoa<br /> The Sertoli cells are much larger than the developing germ cells and span the basement membrane to the lumen of the seminipherous tubules. Their function is provide support to developing germ cells and form the Blood-testis barrier. Each sertoli cells can only support a maximum number of developing germ cells. Therefore, the number of sertoli cells within a testis determine the sperm production capabilities of that individual.<br /> <br /> **peritubular cells - contractile cells surrounding the seminipherous tubules<br /> <br /> ==Comparative Testicular Architecture==<br /> There are species differences between Sertoli cell number and parenchyma composition. In the Boar the parenchyma is made up from many Leydig cells and little lymph space, humans and Rams contain slighly more lymph space and the rat parenchyma is mainly lymph space with few leydig cells.<br /> <br /> ==Function==<br /> '''Scrotum'''<br /> *Temperature sensor<br /> *Protection<br /> *Cooling of testes - evaporative heat loss due to lots of sweat produced by glands in the skin.<br /> <br /> '''Seminipherous Tubules'''<br /> *Production of spermatozoa by Sertoli cells<br /> *Production of hormones by intersticial Leydig cells<br /> *The Blood-Testes Barrier formed by tight junctions between neighbouring Sertoli cells. This barrier prevents White blood cells from entering the adluminal compartment of the seminipherous tubules and autoreacting to the haploid spermatids within it.<br /> <br /> ==Histology==<br /> [[Image:Mature dog testis.jpg|thumb|right|150px|Mature Testis (Dog) - Copyright RVC 2008]]<br /> [[Image:Seminipherous Tubule.jpg|thumb|right|150px|Seminipherous Tubule (Dog) - Copyright RVC 2008]]<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel https://en.wikivet.net/index.php?title=Internal_and_External_Genitalia_Development_-_Anatomy_%26_Physiology&diff=26686 2008-08-11T10:35:03Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> ==Introduction==<br /> Sexual differenciaton by default follows a pathways for development of female internal and external genitalia, requiring no active intervention. Endocrine activity of the testes, production of Androgens by Leydig cells and Mullerian Inhibiting hormone (MIH) by Sertoli cells, is required for sexual differenciation to be diverted down the male genitalia development pathway.<br /> <br /> = Internal Genetalia =<br /> From the primitive reproductive tracts the Internal genitalia can only develop into one gender and so are termed unipotent. <br /> * Male: The primitive male reproductive tract '''The Wolffian Duct''' developes from the '''Mesonephric Duct'''<br /> * Female: The primitive female reproductive tract '''Mullarian Ducts''' develop from the '''Paramesonephric Duct'''<br /> * This is dependent on appropriate hormonal influence.<br /> <br /> <br /> <br /> == Male ==<br /> <br /> <br /> * '''MIH''' from '''Sertoli cells''' and '''Androgens''' from '''Leydig cells''' prevent spontaneous development of female internal genetalia.<br /> * '''Androgens''' actively maintain '''Wolffian Ducts''', which give rise to male internal genetalia:<br /> ** Epididymis<br /> ** Vas Deferens<br /> ** Vesicular Glands/ Seminal Vesicles<br /> * '''MIH''' causes the primitive female reproductive tract Mullarian Ducts to regress.<br /> <br /> <br /> == Female ==<br /> <br /> * Wolffian Ducts spontaneously regress in the absence of Androgens.<br /> * '''Mullarian Ducts''' persist to give rise to female internal genetalia:<br /> ** Oviducts<br /> ** Uterus<br /> ** Cervix<br /> ** Cranial Vagina<br /> * Normal Ovarian activity is NOT essential for the development of normal female internal genetalia as this is the default development pathway.<br /> ----<br /> <br /> = External Genetalia =<br /> External genitalia have the potencial to be either gender and so arebipotencial.<br /> <br /> == Male ==<br /> <br /> * Potential to develop male or female external genetalia. '''Testosterone''' is required to develop male external genetalia. <br /> * Androgen secretion from the Testes induces:<br /> ** '''Urethral folds''' to fuse to allow enclosure of the urethral tube. This, together with the cells from the '''genital swelling''', forms the '''shaft of the Penis'''.<br /> ** '''Genital swellings''' fuse in the midline to allow formation of the '''Scrotum'''<br /> ** '''Genital Tubercle''' expands to give rise to the '''Glans Penis'''<br /> <br /> <br /> <br /> == Female ==<br /> <br /> * Development is ensured by the absence of Testosterone, it is independent of Ovarian endocrine activity.<br /> * '''Urethral folds''' and '''Genital Swellings''' remain separate to form the '''Labia Minora and Majora'''.<br /> * '''Genital tubercle''' forms the '''Clitoris'''<br /> <br /> <br /> <br /> * Exposure of the female tract to Androgens will masculinise external genetalia.<br /> * Failure of proper endocrine communication between the gonads, internal and external genitalia can lead to '''dissociation''' of gonadal and genital sex.<br /> <br /> ----<br /> <br /> = Associated Disorders =<br /> <br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Turner's Syndrome - Anatomy &amp; Physiology|Turner's Syndrome]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Kleinfelter's Syndrome - Anatomy &amp; Physiology|Kleinfelter's Syndrome]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Testicular Feminisation - Anatomy &amp; Physiology|Testicular Feminisation]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Adrenogenital Syndrome - Anatomy &amp; Physiology|Adrenogenital Syndrome]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Intersex - Anatomy &amp; Physiology|Intersex]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Bovine Freemartinism - Anatomy &amp; Physiology|Bovine Freemartinism]]</div>

Amycartmel https://en.wikivet.net/index.php?title=Internal_and_External_Genitalia_Development_-_Anatomy_%26_Physiology&diff=26685 2008-08-11T10:32:58Z

<p>Amycartmel: </p> <hr /> <div>==Introduction==<br /> Sexual differenciaton by default follows a pathways for development of female internal and external genitalia, requiring no active intervention. Endocrine activity of the testes, production of Androgens by Leydig cells and Mullerian Inhibiting hormone (MIH) by Sertoli cells, is required for sexual differenciation to be diverted down the male genitalia development pathway.<br /> <br /> = Internal Genetalia =<br /> From the primitive reproductive tracts the Internal genitalia can only develop into one gender and so are termed unipotent. <br /> * Male: The primitive male reproductive tract '''The Wolffian Duct''' developes from the '''Mesonephric Duct'''<br /> * Female: The primitive female reproductive tract '''Mullarian Ducts''' develop from the '''Paramesonephric Duct'''<br /> * This is dependent on appropriate hormonal influence.<br /> <br /> <br /> <br /> == Male ==<br /> <br /> <br /> * '''MIH''' from '''Sertoli cells''' and '''Androgens''' from '''Leydig cells''' prevent spontaneous development of female internal genetalia.<br /> * '''Androgens''' actively maintain '''Wolffian Ducts''', which give rise to male internal genetalia:<br /> ** Epididymis<br /> ** Vas Deferens<br /> ** Vesicular Glands/ Seminal Vesicles<br /> * '''MIH''' causes the primitive female reproductive tract Mullarian Ducts to regress.<br /> <br /> <br /> == Female ==<br /> <br /> * Wolffian Ducts spontaneously regress in the absence of Androgens.<br /> * '''Mullarian Ducts''' persist to give rise to female internal genetalia:<br /> ** Oviducts<br /> ** Uterus<br /> ** Cervix<br /> ** Cranial Vagina<br /> * Normal Ovarian activity is NOT essential for the development of normal female internal genetalia as this is the default development pathway.<br /> ----<br /> <br /> = External Genetalia =<br /> External genitalia have the potencial to be either gender and so arebipotencial.<br /> <br /> == Male ==<br /> <br /> * Potential to develop male or female external genetalia. '''Testosterone''' is required to develop male external genetalia. <br /> * Androgen secretion from the Testes induces:<br /> ** '''Urethral folds''' to fuse to allow enclosure of the urethral tube. This, together with the cells from the '''genital swelling''', forms the '''shaft of the Penis'''.<br /> ** '''Genital swellings''' fuse in the midline to allow formation of the '''Scrotum'''<br /> ** '''Genital Tubercle''' expands to give rise to the '''Glans Penis'''<br /> <br /> <br /> <br /> == Female ==<br /> <br /> * Development is ensured by the absence of Testosterone, it is independent of Ovarian endocrine activity.<br /> * '''Urethral folds''' and '''Genital Swellings''' remain separate to form the '''Labia Minora and Majora'''.<br /> * '''Genital tubercle''' forms the '''Clitoris'''<br /> <br /> <br /> <br /> * Exposure of the female tract to Androgens will masculinise external genetalia.<br /> * Failure of proper endocrine communication between the gonads, internal and external genitalia can lead to '''dissociation''' of gonadal and genital sex.<br /> <br /> ----<br /> <br /> = Associated Disorders =<br /> <br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Turner's Syndrome - Anatomy &amp; Physiology|Turner's Syndrome]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Kleinfelter's Syndrome - Anatomy &amp; Physiology|Kleinfelter's Syndrome]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Testicular Feminisation - Anatomy &amp; Physiology|Testicular Feminisation]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Adrenogenital Syndrome - Anatomy &amp; Physiology|Adrenogenital Syndrome]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Intersex - Anatomy &amp; Physiology|Intersex]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Bovine Freemartinism - Anatomy &amp; Physiology|Bovine Freemartinism]]</div>

Amycartmel https://en.wikivet.net/index.php?title=Internal_and_External_Genitalia_Development_-_Anatomy_%26_Physiology&diff=26670 2008-08-11T09:50:31Z

<p>Amycartmel: </p> <hr /> <div>==Introduction==<br /> Sexual differenciaton by default follows a pathways for development of female internal and external genitalia, requiring no active intervention. Endocrine activity of the testes, production of Androgens by Leydig cells and Mullerian Inhibiting hormone by Sertoli cells, is required for sexual differenciation to be diverted down the male genitalia development pathway.<br /> <br /> = Internal Genetalia =<br /> * Male: The primitive male reproductive tract '''The Wolffian Duct''' developes from the '''Mesonephric Duct'''<br /> * Female: The primitive female reproductive tract '''Mullarian Ducts''' develop from the '''Paramesonephric Duct'''<br /> * This is dependent on appropriate hormonal influence.<br /> <br /> <br /> <br /> == Male ==<br /> <br /> <br /> * '''MIH''' from '''Sertoli cells''' and '''Androgens''' from '''Leydig cells''' prevent spontaneous development of female internal genetalia.<br /> * '''Androgens''' actively maintain '''Wolffian Ducts''', which give rise to male internal genetalia:<br /> ** Epididymis<br /> ** Vas Deferens<br /> ** Vesicular Glands/ Seminal Vesicles<br /> * '''MIH''' causes Mullarian Ducts to regress<br /> <br /> <br /> == Female ==<br /> <br /> * Wolffian Ducts spontaneously regress in absence of Androgens.<br /> * '''Mullarian Ducts''' persist to give rise to female internal genetalia:<br /> ** Oviducts<br /> ** Uterus<br /> ** Cervix<br /> ** Cranial Vagina<br /> * Normal Ovarian activity is NOT essential for the development of normal female internal genetalia.<br /> ----<br /> <br /> = External Genetalia =<br /> <br /> <br /> == Male ==<br /> <br /> * Potential to develop male of female external genetalia. '''Testosterone''' is required to develop male external genetalia. <br /> * Androgen secretion from the Testes induces:<br /> ** '''Urethral folds''' to fuse to allow enclosure of the urethral tube. This, together with the cells from the '''genital swelling''', forms the '''shaft of the Penis'''.<br /> ** '''Genital swellings''' fuse in the midline to allow formation of the '''Scrotum'''<br /> ** '''Genital Tubercle''' expands to give rise to the '''Glans Penis'''<br /> <br /> <br /> <br /> == Female ==<br /> <br /> * Development is ensured by the absence of Testosterone, it is independent of Ovarian endocrine activity.<br /> * '''Urethral folds''' and '''Genital Swellings''' remain separate to form the '''Labia Minora and Majora'''.<br /> * '''Genital tubercle''' forms the '''Clitoris'''<br /> <br /> <br /> <br /> * Exposure of the female tract to Androgens will masculinise external genetalia.<br /> * Failure of proper endocrine communication between the gonads, internal and external genitalia can lead to '''dissociation''' of gonadal and genital sex.<br /> <br /> ----<br /> <br /> = Sexual Differentiation of the Brain =<br /> <br /> <br /> == Male ==<br /> <br /> * '''Testosterone''' secreted into the blood reaches the brain.<br /> * Converted to Dehydrotestosterone and '''Oestradiol''' by Aromatase enzymes in the Hypothalamus.<br /> * Oestradiol masculinises the brain<br /> <br /> <br /> == Female ==<br /> <br /> * '''Alpha Fetoprotein''' binds Oestradiol, preventing it from crossing the blood-brain barrier.<br /> * Oestradiol cannot access the Hypothalamus<br /> * Protects female brain from masculising effects of Oestradiol.<br /> ----<br /> <br /> = Associated Disorders =<br /> <br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Turner's Syndrome - Anatomy &amp; Physiology|Turner's Syndrome]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Kleinfelter's Syndrome - Anatomy &amp; Physiology|Kleinfelter's Syndrome]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Testicular Feminisation - Anatomy &amp; Physiology|Testicular Feminisation]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Adrenogenital Syndrome - Anatomy &amp; Physiology|Adrenogenital Syndrome]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Intersex - Anatomy &amp; Physiology|Intersex]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Bovine Freemartinism - Anatomy &amp; Physiology|Bovine Freemartinism]]</div>

Amycartmel https://en.wikivet.net/index.php?title=Internal_and_External_Genitalia_Development_-_Anatomy_%26_Physiology&diff=26630 2008-08-11T09:26:02Z

<p>Amycartmel: New page: ==Introduction== = Internal Genetalia = * Male: '''Wolffian Duct''' developes from the '''Mesonephric Duct''' * Female: '''Mullarian Ducts''' develop from the '''Paramesonephric Duct''' ...</p> <hr /> <div>==Introduction==<br /> <br /> <br /> = Internal Genetalia =<br /> * Male: '''Wolffian Duct''' developes from the '''Mesonephric Duct'''<br /> * Female: '''Mullarian Ducts''' develop from the '''Paramesonephric Duct'''<br /> * This is dependent on appropriate hormonal influence.<br /> <br /> <br /> <br /> == Male ==<br /> <br /> <br /> * '''MIH''' from '''Sertoli cells''' and '''Androgens''' from '''Leydig cells''' prevent spontaneous development of female internal genetalia.<br /> * '''Androgens''' actively maintain '''Wolffian Ducts''', which give rise to male internal genetalia:<br /> ** Epididymis<br /> ** Vas Deferens<br /> ** Vesicular Glands/ Seminal Vesicles<br /> * '''MIH''' causes Mullarian Ducts to regress<br /> <br /> <br /> == Female ==<br /> <br /> * Wolffian Ducts spontaneously regress in absence of Androgens.<br /> * '''Mullarian Ducts''' persist to give rise to female internal genetalia:<br /> ** Oviducts<br /> ** Uterus<br /> ** Cervix<br /> ** Cranial Vagina<br /> * Normal Ovarian activity is NOT essential for the development of normal female internal genetalia.<br /> ----<br /> <br /> = External Genetalia =<br /> <br /> <br /> == Male ==<br /> <br /> * Potential to develop male of female external genetalia. '''Testosterone''' is required to develop male external genetalia. <br /> * Androgen secretion from the Testes induces:<br /> ** '''Urethral folds''' to fuse to allow enclosure of the urethral tube. This, together with the cells from the '''genital swelling''', forms the '''shaft of the Penis'''.<br /> ** '''Genital swellings''' fuse in the midline to allow formation of the '''Scrotum'''<br /> ** '''Genital Tubercle''' expands to give rise to the '''Glans Penis'''<br /> <br /> <br /> <br /> == Female ==<br /> <br /> * Development is ensured by the absence of Testosterone, it is independent of Ovarian endocrine activity.<br /> * '''Urethral folds''' and '''Genital Swellings''' remain separate to form the '''Labia Minora and Majora'''.<br /> * '''Genital tubercle''' forms the '''Clitoris'''<br /> <br /> <br /> <br /> * Exposure of the female tract to Androgens will masculinise external genetalia.<br /> * Failure of proper endocrine communication between the gonads, internal and external genitalia can lead to '''dissociation''' of gonadal and genital sex.<br /> <br /> ----<br /> <br /> = Sexual Differentiation of the Brain =<br /> <br /> <br /> == Male ==<br /> <br /> * '''Testosterone''' secreted into the blood reaches the brain.<br /> * Converted to Dehydrotestosterone and '''Oestradiol''' by Aromatase enzymes in the Hypothalamus.<br /> * Oestradiol masculinises the brain<br /> <br /> <br /> == Female ==<br /> <br /> * '''Alpha Fetoprotein''' binds Oestradiol, preventing it from crossing the blood-brain barrier.<br /> * Oestradiol cannot access the Hypothalamus<br /> * Protects female brain from masculising effects of Oestradiol.<br /> ----<br /> <br /> = Associated Disorders =<br /> <br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Turner's Syndrome - Anatomy &amp; Physiology|Turner's Syndrome]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Kleinfelter's Syndrome - Anatomy &amp; Physiology|Kleinfelter's Syndrome]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Testicular Feminisation - Anatomy &amp; Physiology|Testicular Feminisation]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Adrenogenital Syndrome - Anatomy &amp; Physiology|Adrenogenital Syndrome]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Intersex - Anatomy &amp; Physiology|Intersex]]<br /> <br /> * [[Fertilisation, Implantation and Early Embryonic Development -Bovine Freemartinism - Anatomy &amp; Physiology|Bovine Freemartinism]]</div>

Amycartmel https://en.wikivet.net/index.php?title=Sexual_Differentiation_-_Anatomy_%26_Physiology&diff=26629 2008-08-11T09:25:48Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Fertilisation.2C_Implantation_and_Early_Embryonic_Development|'''BACK TO FERTILISATION , IMPLANTATION and EARLY EMBRYONIC DEVELOPMENT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> <br /> <br /> [[Image:Overview of Sexual Differentiation.jpg|thumb|right|150px|Overview of Sexual Differentiation,Copyright RVC 2008]]<br /> <br /> = Genetic Sex =<br /> * Established at the time of '''fertilisation'''.<br /> * The foetus receives its genetic endowment in two equal portions from the male gamete ('''Spermatozoon''') and female gamete ('''Oocyte''').<br /> * The X sex chromosome is larger than the Y sex chromosome.<br /> * '''Females''' have '''XX''' chromosomes. All oocytes contain one X chromosome, they are the '''homogametic''' sex.<br /> * '''Males''' have '''XY''' chromosomes. Spermatozoa form two distinct populations, one containing X chromosomes and one containing Y chromosomes. They are the '''heterogametic''' sex.<br /> <br /> <br /> * The '''Y''' chromosome is required to '''initiate male development'''.<br /> * In absence of the Y chromosome, female gonads (Ovaries) will develop.<br /> * The prime male determining gene is '''SRY''' (sex determining region of the Y chromosome). <br /> <br /> * SRY is a very small piece of DNA that acts as a molecular switch to regulate structural genes and autosomal chromosomes, determining if and when they are to be activated. <br /> * SRY encodes the protein '''Testes Determining Factor''' (TDF)<br /> * The presence of SRY alone is sufficient to ensure development of male gonads (Testes).<br /> * Female is the default sex, in absence of SRY female gonads (Ovaries) will develop.<br /> <br /> <br /> * Subsequent gonadal development is dependent on a normal population of '''germ cells'''.<br /> * Normal Oocyte growth requires the activity of both X chromosomes.<br /> * Normal Spermatogenesis requires the activity of no more than one X chromosome.<br /> <br /> <br /> * Early development of gonads proceeds similarly in both sexes. The gonads are derived from two distinct tissues:<br /> ** '''Somatic mesenchymal tissue''' forms the matrix of the gonad<br /> ** '''Primordial germ cells''' form the gametes<br /> <br /> <br /> * '''Genital ridge''' forms from somatic mesenchyme.<br /> * Primordial germ cells migrate to the genital ridge.<br /> * At this stage it is not possible to discriminate between male and female gonads.<br /> * Y chromosomal determination of gonadal sex is only visible when primordial germ cell colonisation is complete.<br /> <br /> <br /> == Male ==<br /> <br /> * Sex cord cells proliferate to form the testes cord. During this period '''SRY''' is expressed for the first time within '''Sertoli cells''' (SRY is NOT expressed in primordial germ cells).<br /> * Sex cords with a basement membrane become '''Semniferous Cords''' which give rise to '''Semniferous Tubules'''.<br /> * '''Within the semniferous cords''' are two cell populations:<br /> ** '''Primordial germ cells''' - Prospermatogonia which give rise to '''Spermatozoa'''<br /> ** '''Mesodermal cord cells''' which give rise to '''Sertoli cells'''<br /> * '''Between cords''', the loose mesenchyme undergoes '''vascularisation''' and develops as '''stromal tissue'''.<br /> * Within the stromal tissue, cells condense into clusters to form specialized endocrine units - the interstitial '''Leydig Cells'''<br /> <br /> <br /> == Female ==<br /> <br /> * At the time the male gonad is undergoing marked changes under the direction of SRY, the female gonad continues to appear indifferent and does not express SRY.<br /> * Small clusters of mesenchyme surround the germ cells to initiate formation of '''Primary Follicles''', characteristic of the Ovary.<br /> * In follicles:<br /> ** '''Mesenchymal cells''' give rise to '''Granulosa cells'''<br /> ** '''Germ cells''' give rise to '''Oocytes'''<br /> <br /> <br /> <br /> == Foetal sex differentiation ==<br /> <br /> * Endocrine activity of the Ovaries is NOT essential for sex differentiation during foetal life, abnormal ovarian development will have no effect until puberty.<br /> * Testes secrete two essential hormones: <br /> ** '''Steroidal hormones''' (mainly C19 androgens) from '''Leydig cells'''<br /> ** '''Mullarian Inhibiting Hormone''' (MIH) also known as '''Anti-Mullarian Hormone''' (AMH) from '''Sertoli Cells'''<br /> * In absence of these testicular hormones, female differentiation occurs.<br /> * Thus, sexual differentiation must be actively diverted down the male route, the female route requires no active intervention.<br /> <br /> ----<br /> <br /> <br /> <br /> &lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Fertilisation.2C_Implantation_and_Early_Embryonic_Development|'''BACK TO FERTILISATION , IMPLANTATION and EARLY EMBRYONIC DEVELOPMENT''']]&lt;/center&gt;&lt;/big&gt;</div>

Amycartmel https://en.wikivet.net/index.php?title=Penis_-_Anatomy_%26_Physiology&diff=26621 2008-08-11T09:13:40Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> <br /> ==Introduction==<br /> <br /> ==External Genitalia development==<br /> <br /> <br /> ==Penis Structure==</div>

Amycartmel https://en.wikivet.net/index.php?title=Spermatogenesis_and_Spermiation_-_Anatomy_%26_Physiology&diff=26620 2008-08-11T09:08:49Z

<p>Amycartmel: New page: &lt;big&gt;&lt;center&gt;'''BACK TO REPRODUCTIVE SYSTEM'''&lt;/center&gt;&lt;/big&gt; &lt;big&gt;&lt;center&gt;'''BACK TO MALE REPRODUCTIVE TRACT'''&lt;/ce...</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;</div>

Amycartmel https://en.wikivet.net/index.php?title=Penis_-_Anatomy_%26_Physiology&diff=26619 2008-08-11T09:08:41Z

<p>Amycartmel: New page: &lt;big&gt;&lt;center&gt;'''BACK TO REPRODUCTIVE SYSTEM'''&lt;/center&gt;&lt;/big&gt; &lt;big&gt;&lt;center&gt;'''BACK TO MALE REPRODUCTIVE TRACT'''&lt;/ce...</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;</div>

Amycartmel https://en.wikivet.net/index.php?title=File:Seminipherous_Tubule.jpg&diff=26618 2008-08-11T09:04:50Z

<p>Amycartmel: </p> <hr /> <div></div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26617 2008-08-11T09:04:31Z

<p>Amycartmel: /* Histology */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> *'''Scrotum '''<br /> **Skin - Contains many sweat glands, thermosensitive receptors and sympathetic nerves.<br /> **Tunica Dartos - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures, as it can maintain sustained contraction, and letting the testes lower in hot weather, increasing the surface area for heat loss from the skin.<br /> **Scrotal fascia<br /> **Parietal Vaginal Tunic - The first peritoneam layer taken into the scrotum by the peritoneum fusion with the gubernaculum during testicular descent.<br /> *'''Vaginal Cavity''' - A potential space<br /> *'''Testicular Capsule'''<br /> **Visceral Vaginal Tunic - The second peritoneum layer within the scrotum. This layer is closely applied to the Tunica Albuginea.<br /> **Tunica Albuginea - A connective tissue layer containing some smooth muscle fibres. The Tunica Albuginea sends projections from the capsules into the testicular parenchyma that join up with the mediastinum of the testis forming lobules. Contraction and relaxation of the smooth muscle fibres within the Tunica Albuginea in response to Acetylcholine and Norepinephrine results in a pumping action facilitating the flow of spermatozoa through the tubules of the testes.<br /> *'''Testicular Parenchyma'''<br /> **Interstitial Leydig cells - Produce the androgen testosterone important for supporting spermatogenesis.<br /> **Cappilaries, Lymphatic vessels, connective tissue.<br /> *'''Tubular Compartment'''<br /> **Seminipherous Tubules - Make up highly convoluted tubule network within the teste parenchyma. These seminipherous tubules connect to Rete tubules. The Seminipherous epithelium making up the tubules can be devided into two compartments seperated by junctional complexes between the somatic Sertoli cells within the epithelium:<br /> <br /> ***Basal Compartment - containing spermatogonia, proliferating germ cells.<br /> ***Adluminal Compartment - Containing Spermatocytes, Spermatids and spermatozoa<br /> <br /> The Sertoli cells are much larger than the developing germ cells and span the basement membrane to the lumen of the seminipherous tubules. Their function is provide support to developing germ cells and form the Blood-testis barrier. Each sertoli cells can only support a maximum number of developing germ cells. Therefore, the number of sertoli cells within a testis determine the sperm production capabilities of that individual.<br /> <br /> **peritubular cells - contractile cells surrounding the seminipherous tubules<br /> <br /> ==Comparative Testicular Architecture==<br /> There are species differences between Sertoli cell number and parenchyma composition. In the Boar the parenchyma is made up from many Leydig cells and little lymph space, humans and Rams contain slighly more lymph space and the rat parenchyma is mainly lymph space with few leydig cells.<br /> <br /> ==Function==<br /> '''Scrotum'''<br /> *Temperature sensor<br /> *Protection<br /> *Cooling of testes - evaporative heat loss due to lots of sweat produced by glands in the skin.<br /> <br /> '''Seminipherous Tubules'''<br /> *Production of spermatozoa by Sertoli cells<br /> *Production of hormones by intersticial Leydig cells<br /> *The Blood-Testes Barrier formed by tight junctions between neighbouring Sertoli cells. This barrier prevents White blood cells from entering the adluminal compartment of the seminipherous tubules and autoreacting to the haploid spermatids within it.<br /> <br /> ==Histology==<br /> [[Image:Mature dog testis.jpg|thumb|right|150px|Mature Testis (Dog) - Copyright RVC 2008]]<br /> [[Image:Seminipherous Tubule.jpg|thumb|right|150px|Seminipherous Tubule (Dog) - Copyright RVC 2008]]<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel https://en.wikivet.net/index.php?title=File:Mature_dog_testis.jpg&diff=26616 2008-08-11T09:00:14Z

<p>Amycartmel: </p> <hr /> <div></div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26615 2008-08-11T08:59:37Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> *'''Scrotum '''<br /> **Skin - Contains many sweat glands, thermosensitive receptors and sympathetic nerves.<br /> **Tunica Dartos - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures, as it can maintain sustained contraction, and letting the testes lower in hot weather, increasing the surface area for heat loss from the skin.<br /> **Scrotal fascia<br /> **Parietal Vaginal Tunic - The first peritoneam layer taken into the scrotum by the peritoneum fusion with the gubernaculum during testicular descent.<br /> *'''Vaginal Cavity''' - A potential space<br /> *'''Testicular Capsule'''<br /> **Visceral Vaginal Tunic - The second peritoneum layer within the scrotum. This layer is closely applied to the Tunica Albuginea.<br /> **Tunica Albuginea - A connective tissue layer containing some smooth muscle fibres. The Tunica Albuginea sends projections from the capsules into the testicular parenchyma that join up with the mediastinum of the testis forming lobules. Contraction and relaxation of the smooth muscle fibres within the Tunica Albuginea in response to Acetylcholine and Norepinephrine results in a pumping action facilitating the flow of spermatozoa through the tubules of the testes.<br /> *'''Testicular Parenchyma'''<br /> **Interstitial Leydig cells - Produce the androgen testosterone important for supporting spermatogenesis.<br /> **Cappilaries, Lymphatic vessels, connective tissue.<br /> *'''Tubular Compartment'''<br /> **Seminipherous Tubules - Make up highly convoluted tubule network within the teste parenchyma. These seminipherous tubules connect to Rete tubules. The Seminipherous epithelium making up the tubules can be devided into two compartments seperated by junctional complexes between the somatic Sertoli cells within the epithelium:<br /> <br /> ***Basal Compartment - containing spermatogonia, proliferating germ cells.<br /> ***Adluminal Compartment - Containing Spermatocytes, Spermatids and spermatozoa<br /> <br /> The Sertoli cells are much larger than the developing germ cells and span the basement membrane to the lumen of the seminipherous tubules. Their function is provide support to developing germ cells and form the Blood-testis barrier. Each sertoli cells can only support a maximum number of developing germ cells. Therefore, the number of sertoli cells within a testis determine the sperm production capabilities of that individual.<br /> <br /> **peritubular cells - contractile cells surrounding the seminipherous tubules<br /> <br /> ==Comparative Testicular Architecture==<br /> There are species differences between Sertoli cell number and parenchyma composition. In the Boar the parenchyma is made up from many Leydig cells and little lymph space, humans and Rams contain slighly more lymph space and the rat parenchyma is mainly lymph space with few leydig cells.<br /> <br /> ==Function==<br /> '''Scrotum'''<br /> *Temperature sensor<br /> *Protection<br /> *Cooling of testes - evaporative heat loss due to lots of sweat produced by glands in the skin.<br /> <br /> '''Seminipherous Tubules'''<br /> *Production of spermatozoa by Sertoli cells<br /> *Production of hormones by intersticial Leydig cells<br /> *The Blood-Testes Barrier formed by tight junctions between neighbouring Sertoli cells. This barrier prevents White blood cells from entering the adluminal compartment of the seminipherous tubules and autoreacting to the haploid spermatids within it.<br /> <br /> ==Histology==<br /> [[Image:Mature dog testis.jpg|thumb|right|150px|Mature Testis (Dog) - Copyright RVC 2008]]<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26614 2008-08-11T01:26:38Z

<p>Amycartmel: /* Testicular Architecture */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> *'''Scrotum '''<br /> **Skin - Contains many sweat glands, thermosensitive receptors and sympathetic nerves.<br /> **Tunica Dartos - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures, as it can maintain sustained contraction, and letting the testes lower in hot weather, increasing the surface area for heat loss from the skin.<br /> **Scrotal fascia<br /> **Parietal Vaginal Tunic - The first peritoneam layer taken into the scrotum by the peritoneum fusion with the gubernaculum during testicular descent.<br /> *'''Vaginal Cavity''' - A potential space<br /> *'''Testicular Capsule'''<br /> **Visceral Vaginal Tunic - The second peritoneum layer within the scrotum. This layer is closely applied to the Tunica Albuginea.<br /> **Tunica Albuginea - A connective tissue layer containing some smooth muscle fibres. The Tunica Albuginea sends projections from the capsules into the testicular parenchyma that join up with the mediastinum of the testis forming lobules. Contraction and relaxation of the smooth muscle fibres within the Tunica Albuginea in response to Acetylcholine and Norepinephrine results in a pumping action facilitating the flow of spermatozoa through the tubules of the testes.<br /> *'''Testicular Parenchyma'''<br /> **Interstitial Leydig cells - Produce the androgen testosterone important for supporting spermatogenesis.<br /> **Cappilaries, Lymphatic vessels, connective tissue.<br /> *'''Tubular Compartment'''<br /> **Seminipherous Tubules - Make up highly convoluted tubule network within the teste parenchyma. These seminipherous tubules connect to Rete tubules. The Seminipherous epithelium making up the tubules can be devided into two compartments seperated by junctional complexes between the somatic Sertoli cells within the epithelium:<br /> <br /> ***Basal Compartment - containing spermatogonia, proliferating germ cells.<br /> ***Adluminal Compartment - Containing Spermatocytes, Spermatids and spermatozoa<br /> <br /> The Sertoli cells are much larger than the developing germ cells and span the basement membrane to the lumen of the seminipherous tubules. Their function is provide support to developing germ cells and form the Blood-testis barrier. The number of sertoli cells within a testis determine the sperm production capabilities of that individual.<br /> <br /> **peritubular cells - contractile cells surrounding the seminipherous tubules<br /> <br /> ==Comparative Testicular Architecture==<br /> <br /> ==Function==<br /> '''Scrotum'''<br /> *Temperature sensor<br /> *Protection<br /> *Cooling of testes - evaporative heat loss due to lots of sweat produced by glands in the skin.<br /> <br /> '''Seminipherous Tubules'''<br /> *Production of spermatozoa by Sertoli cells<br /> *Production of hormones by intersticial Leydig cells<br /> <br /> ==Histology==<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26613 2008-08-11T01:05:38Z

<p>Amycartmel: /* Function */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> *'''Scrotum '''<br /> **Skin - Contains many sweat glands, thermosensitive receptors and sympathetic nerves.<br /> **Tunica Dartos - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures, as it can maintain sustained contraction, and letting the testes lower in hot weather, increasing the surface area for heat loss from the skin.<br /> **Scrotal fascia<br /> **Parietal Vaginal Tunic - The first peritoneam layer taken into the scrotum by the peritoneum fusion with the gubernaculum during testicular descent.<br /> *'''Vaginal Cavity''' - A potential space<br /> *'''Testicular Capsule'''<br /> **Visceral Vaginal Tunic - The second peritoneum layer within the scrotum. This layer is closely applied to the Tunica Albuginea.<br /> **Tunica Albuginea - A connective tissue layer containing some smooth muscle fibres. The Tunica Albuginea sends projections from the capsules into the testicular parenchyma that join up with the mediastinum of the testis forming lobules. Contraction and relaxation of the smooth muscle fibres within the Tunica Albuginea in response to Acetylcholine and Norepinephrine results in a pumping action facilitating the flow of spermatozoa through the tubules of the testes.<br /> *'''Testicular Parenchyma'''<br /> **Interstitial Leydig cells - produce testosterone.<br /> **Cappilaries, Lymphatic vessels, connective tissue.<br /> *'''Tubular Compartment'''<br /> **Seminipherous cells - highly convoluted, connect to rete tubules<br /> **Developing germ cells<br /> **peritubular cells<br /> <br /> ==Comparative Testicular Architecture==<br /> <br /> ==Function==<br /> '''Scrotum'''<br /> *Temperature sensor<br /> *Protection<br /> *Cooling of testes - evaporative heat loss due to lots of sweat produced by glands in the skin.<br /> <br /> '''Seminipherous Tubules'''<br /> *Production of spermatozoa by Sertoli cells<br /> *Production of hormones by intersticial Leydig cells<br /> <br /> ==Histology==<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26612 2008-08-11T00:57:54Z

<p>Amycartmel: /* Testicular Architecture */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> *'''Scrotum '''<br /> **Skin - Contains many sweat glands, thermosensitive receptors and sympathetic nerves.<br /> **Tunica Dartos - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures, as it can maintain sustained contraction, and letting the testes lower in hot weather, increasing the surface area for heat loss from the skin.<br /> **Scrotal fascia<br /> **Parietal Vaginal Tunic - The first peritoneam layer taken into the scrotum by the peritoneum fusion with the gubernaculum during testicular descent.<br /> *'''Vaginal Cavity''' - A potential space<br /> *'''Testicular Capsule'''<br /> **Visceral Vaginal Tunic - The second peritoneum layer within the scrotum. This layer is closely applied to the Tunica Albuginea.<br /> **Tunica Albuginea - A connective tissue layer containing some smooth muscle fibres. The Tunica Albuginea sends projections from the capsules into the testicular parenchyma that join up with the mediastinum of the testis forming lobules. Contraction and relaxation of the smooth muscle fibres within the Tunica Albuginea in response to Acetylcholine and Norepinephrine results in a pumping action facilitating the flow of spermatozoa through the tubules of the testes.<br /> *'''Testicular Parenchyma'''<br /> **Interstitial Leydig cells - produce testosterone.<br /> **Cappilaries, Lymphatic vessels, connective tissue.<br /> *'''Tubular Compartment'''<br /> **Seminipherous cells - highly convoluted, connect to rete tubules<br /> **Developing germ cells<br /> **peritubular cells<br /> <br /> ==Comparative Testicular Architecture==<br /> <br /> ==Function==<br /> <br /> ==Histology==<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26611 2008-08-11T00:31:59Z

<p>Amycartmel: /* Testicular Architecture */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> *'''Scrotum '''<br /> **Skin<br /> **Tunica Dartos - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures as it can maintain sustained contraction.<br /> **Scrotal fascia<br /> **Parietal Vaginal Tunic - Peritoneam layer<br /> *'''Vaginal Cavity''' - A potential space<br /> *'''Testicular Capsule'''<br /> **Visceral Vaginal Tunic - peritoneum layer<br /> **Tunica Albuginea<br /> *'''Testicular Parenchyma'''<br /> **Seminipherus tubules<br /> **Interstitial Leydig cells<br /> **Cappilaries, Lymphatic vessels, connective tissue<br /> *'''Tubular Compartment'''<br /> **Seminipherous cells<br /> **Developing germ cells<br /> **peritubular cells<br /> <br /> ==Comparative Testicular Architecture==<br /> <br /> ==Function==<br /> <br /> ==Histology==<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26610 2008-08-11T00:27:50Z

<p>Amycartmel: /* Testicular Architecture */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> *'''Scrotum '''<br /> **Skin<br /> **'''Tunica Dartos''' - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures as it can maintain sustained contraction.<br /> **'''Scrotal fascia'''<br /> **'''Parietal Vaginal Tunic - Peritoneam layer<br /> *'''Vaginal Cavity''' - A potential space<br /> *'''Testicular Capsule'''<br /> **'''Visceral Vaginal Tunic''' - peritoneum layer<br /> **'''Tunica Albuginea'''<br /> *'''Testicular Parenchyma'''<br /> **'''Seminipherus tubules'''<br /> **'''Interstitial Leydig cells'''<br /> **Cappilaries, Lymphatic vessels, connective tissue<br /> *'''Rete tubules'''<br /> <br /> ==Comparative Testicular Architecture==<br /> <br /> ==Function==<br /> <br /> ==Histology==<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26609 2008-08-11T00:21:43Z

<p>Amycartmel: /* Comparative Testicular Architecture */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> 1.'''Scrotal Skin'''<br /> <br /> 2.'''Tunica Dartos''' - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures as it can maintain sustained contraction.<br /> <br /> 3.'''Scrotal fascia'''<br /> <br /> 4.'''Parietal Vaginal Tunic - Peritoneam layer<br /> <br /> 5.'''Vaginal Cavity''' - A potential space<br /> <br /> 6.'''Visceral Vaginal Tunic''' - peritoneum layer<br /> <br /> 7.'''Tunica Albuginea'''<br /> <br /> 8.'''Seminipherus tubules'''<br /> <br /> 9.'''Rete tubules'''<br /> <br /> 10.'''Mediastinum'''<br /> <br /> ==Comparative Testicular Architecture==<br /> <br /> ==Function==<br /> <br /> ==Histology==<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26608 2008-08-11T00:18:45Z

<p>Amycartmel: /* Testicular Architecture */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> 1.'''Scrotal Skin'''<br /> <br /> 2.'''Tunica Dartos''' - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures as it can maintain sustained contraction.<br /> <br /> 3.'''Scrotal fascia'''<br /> <br /> 4.'''Parietal Vaginal Tunic - Peritoneam layer<br /> <br /> 5.'''Vaginal Cavity''' - A potential space<br /> <br /> 6.'''Visceral Vaginal Tunic''' - peritoneum layer<br /> <br /> 7.'''Tunica Albuginea'''<br /> <br /> 8.'''Seminipherus tubules'''<br /> <br /> 9.'''Rete tubules'''<br /> <br /> 10.'''Mediastinum'''<br /> <br /> ===Comparative Testicular Architecture===<br /> <br /> ==Function==<br /> <br /> ==Histology==<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26607 2008-08-11T00:17:07Z

<p>Amycartmel: /* Testicular Architecture */</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> 1.'''Scrotal Skin'''<br /> 2.'''Tunica Dartos''' - Smooth muscle layer found below the skin of the scrotum. Smooth muscle tone controlled by Androgens released in response to temperature changes detected by sensory nerves within the scrotal skin. The tunica dartos is responsible for holding the testes close to the body during cold temperatures as it can maintain sustained contraction.<br /> 3.'''Scrotal fascia'''<br /> 4.'''Parietal Vaginal Tunic - Peritoneam layer<br /> 5.'''Vaginal Cavity''' - A potential space<br /> 6.'''Visceral Vaginal Tunic''' - peritoneum layer<br /> 7.'''Tunica Albuginea'''<br /> 8.'''Seminipherus tubules'''<br /> 9.'''Rete tubules'''<br /> 10.'''Mediastinum'''<br /> <br /> ===Comparative Testicular Architecture===<br /> <br /> ==Function==<br /> <br /> ==Histology==<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel https://en.wikivet.net/index.php?title=Accessory_Sex_Glands_-_Anatomy_%26_Physiology&diff=26606 2008-08-10T23:50:22Z

<p>Amycartmel: New page: &lt;big&gt;&lt;center&gt;'''BACK TO REPRODUCTIVE SYSTEM'''&lt;/center&gt;&lt;/big&gt; &lt;big&gt;&lt;center&gt;'''BACK TO MALE REPRODUCTIVE TRACT'''&lt;/ce...</p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26605 2008-08-10T23:49:51Z

<p>Amycartmel: </p> <hr /> <div>&lt;big&gt;&lt;center&gt;[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]&lt;/center&gt;&lt;/big&gt;<br /> &lt;big&gt;&lt;center&gt;[[Reproductive_System#Male Reproductive Tract|'''BACK TO MALE REPRODUCTIVE TRACT''']]&lt;/center&gt;&lt;/big&gt;<br /> ==Introduction==<br /> <br /> ==Testicular Architecture==<br /> <br /> ===Comparative Testicular Architecture===<br /> <br /> ==Function==<br /> <br /> ==Histology==<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel https://en.wikivet.net/index.php?title=Testes_and_Epididymis_-_Anatomy_%26_Physiology&diff=26604 2008-08-10T23:37:18Z

<p>Amycartmel: /* Vasculature */</p> <hr /> <div>==Introduction==<br /> <br /> ==Testicular Architecture==<br /> <br /> ===Comparative Testicular Architecture===<br /> <br /> ==Function==<br /> <br /> ==Histology==<br /> <br /> ==Vasculature==<br /> *The '''Testicular Artery''' a direct branch off the aorta. <br /> **This has important implications when performing castration procedures as the pressure within the artery will be very high and so it is imperitive to tie the artery off properly.<br /> **The testicular artery is highly convoluted and contains many elastic fibres within its wall. It acts as a pulse pressure eliminator between the inguinal ring and surface of the teste, minimising the differance between systolic and diastolic pressures within the artery (usually 40mmHg). <br /> *The '''Pampiniform Plexus'''<br /> **The network of testicular veins that surround the testicular artery providing the testes with a countercurrent heat exchanger.<br /> **The testes require a temperature of 33°C in order for maintaining spermatogenesis, 3-6°C lower than core body temperature. This is achieved by the countercurrent exchange system between the pampiniform plexus and the testicular artery. Heat is transfered from the warmer blood in the testicular artery to the cooler blood returning from the testes in the testicular veins. The testicular veins run close to the surface of the scrotum so the blood within them is cooled by heat radiation from the skin of the scrotum.<br /> <br /> ==Testicular Descent==<br /> The developing testes start off in the abdomen. They develop from somatic mesenchymal cells in the genital ridge found caudal to the developing kidneys, around the tenth [[Spinal_Column_-_Anatomy_%26_Physiology#Thoracic_Vertebrae|thoracic vertebra]]. The testes migrate caudally and retroperitoneally towards the inguinal canal and scrotum. This translocation of the testis is the result of growth and contraction of the Gubernaculum aswell as the relative growth of associated viscera within the abdomen. The gubernaculum is a ligamentous structure extending from the site of the future scrotum, through the inguinal ring to the caudal testis. In the inguinal region the distal portion of the gubernaculum fuses with the covering peritoneum before its descent, forming the visceral and parietal vaginal tunics. These two layers of peritoneum cover the testes within the scrotum and are seperated by the vaginal cavity. Once the testes have descended into the scrotum the inguinal canal contracts behind them to keep them in place.</div>

Amycartmel