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Male Reproductive Tract - Horse Anatomy (view source)
Revision as of 13:52, 25 November 2022
, 13:52, 25 November 2022no edit summary
The parenchyma of the testes is composed of the '''semniferous tubules''', '''rete testis''' and '''efferent ducts'''. The '''semniferous tubules''' are the site of [[Spermatogenesis and Spermiation - Anatomy & Physiology|spermatogenesis]]. The walls of the semniferous tubules contain '''spermatogenic cells''' and their sustentacular cells, which are known as '''sertoli cells'''. The sertoli cells give support and also produce hormones. They regulate [[Spermatogenesis and Spermiation - Anatomy & Physiology|spermatogenesis]] and the release of spermatozoa into the lumen of the semniferous tubules. Each semniferous tubule opens into a network of tubules called the '''rete testis'''. Each rete testis is drained by multiple '''efferent ducts''' which perforate the capsule of the testes to enter the '''head of the epididymis'''. The interstitial tissue between semniferous tubules contains '''Leydig cells'''. These cells produce androgens, such as '''testosterone'''.
The parenchyma of the testes is composed of the '''semniferous tubules''', '''rete testis''' and '''efferent ducts'''. The '''semniferous tubules''' are the site of [[Spermatogenesis and Spermiation - Anatomy & Physiology|spermatogenesis]]. The walls of the semniferous tubules contain '''spermatogenic cells''' and their sustentacular cells, which are known as '''sertoli cells'''. The sertoli cells give support and also produce hormones. They regulate [[Spermatogenesis and Spermiation - Anatomy & Physiology|spermatogenesis]] and the release of spermatozoa into the lumen of the semniferous tubules. Each semniferous tubule opens into a network of tubules called the '''rete testis'''. Each rete testis is drained by multiple '''efferent ducts''' which perforate the capsule of the testes to enter the '''head of the epididymis'''. The interstitial tissue between semniferous tubules contains '''Leydig cells'''. These cells produce androgens, such as '''testosterone'''.
The Blood-Testes Barrier is formed by tight junctions between neighbouring Sertoli cells. This barrier prevents leukocytes from entering the adluminal compartment of the seminipherous tubules and autoreacting to the haploid spermatids within it.
The '''Blood-Testes Barrier''' is formed by tight junctions between neighbouring Sertoli cells. This barrier prevents leukocytes from entering the adluminal compartment of the seminipherous tubules and autoreacting to the haploid spermatids within it.
{{Template:Learning
|videos = [[Video: Equine Testes|Dissection of the equine testicle]]
}}
===Epididymis===
===Epididymis===
====Ischiocavernosus Muscles====
====Ischiocavernosus Muscles====
These are paired muscles located at the root of the penis which arise from the ischial arch and enclose the '''crura'''. They connect the penis to the ischial arch of the pelvis.
These are paired muscles located at the root of the penis which arise from the ischial arch and enclose the '''crura'''. They connect the penis to the ischial arch of the pelvis.
====Retractor penis Muscles====
====Retractor Penis Muscles====
These paired muscles originate on the caudal vertebrae and insert on the ventrolateral surfaces of the penis. They follow the bulbospongiosus muscle to the apex of the penis.
These paired muscles originate on the caudal vertebrae and insert on the ventrolateral surfaces of the penis. They follow the bulbospongiosus muscle to the apex of the penis.
===Vasculature===
===Vasculature===
The artery of the penis is a direct branch off the internal pudendal artery. It splits into three branches:
The artery of the penis is a direct branch off the '''internal pudendal artery'''. It splits into three branches:
*Artery of the bulb – supplies the corpus spongiosus
*Artery of the bulb – supplies the corpus spongiosus
*Deep artery of the penis – supplies the corpus cavernosum
*Deep artery of the penis – supplies the corpus cavernosum
*Dorsal artery of the penis – supplies the glans penis
*Dorsal artery of the penis – supplies the glans penis
The prepuce covering the flaccid penis is supplied by anastamosis between the external pudendal artery and the artery of the penis.
The '''prepuce''' covering the flaccid penis is supplied by anastamosis between the '''external pudendal artery''' and the '''artery of the penis'''. In the stallion, there are additional anastamoses between the '''dorsal artery of the penis''' and the '''obturator artery'''.
===Innervation===
===Innervation===
*Mostly parasympathetic from the paired pudendal nerves
*Mostly parasympathetic from the paired '''pudendal nerves'''
*The glans penis and internal lamina of the prepuce are heavily infiltrated by sensory nerve endings responsible for stimulating ejaculation
*The glans penis and internal lamina of the prepuce are heavily infiltrated by sensory nerve endings, responsible for stimulating ejaculation
===Lymphatics===
===Lymphatics===
Lymph from the penis and prepuce drains into the superficial inguinal lymph nodes.
Lymph from the penis and prepuce drains into the '''superficial inguinal lymph nodes'''.
{{Learning
|videos = [https://wikivet.mediacore.tv/media/equine-penis-potcast Equine penis potcast]
}}
==Accessory Sex Glands==
==Accessory Sex Glands==
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. Development and function of the accessory sex glands is androgen dependant.
===Bulbourethral Glands===
The paired bulbourethral glands are found near the ischial arch either side of, and dorsal to, the urethra. They are approximately the size of a cherry. These are very dense glands containing a lot of fibrous connective tissue.
===Prostate Gland===
The prostate is a singular gland, found at the junction between the bladder and the urethra. The stallion has only the compact part of the prostate ('''corpus prostate'''), which is a compact body of tissue found external to the urethra.
===Ampullary Glands===
These paired glands are 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. The glands are connected to the urethra via the '''ejaculatory duct'''.
===Vesicular Glands===
The paired vesicular glands are found dorsocranial to the pelvic urethra. In the horse, the '''excretory duct''' from the vesicular glands join the ductus deferens to form the '''ejaculatory duct'''. They are also relatively large in the horse and are hollow with a thick, muscular wall and smooth surface.
==Clinical Links==
*[[Paraphimosis]] is the protrusion of the penis and inability to retract it.
*[[Castration Complications - Horse|Castration complications]]
[[Category:To Do - AP Review]]
==Webinars==
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