Difference between revisions of "Avian Male Reproductive Tract - Anatomy & Physiology"
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− | + | <big><center>[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]</center></big> | |
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+ | <big><center>[[Reproductive_System#Exotics|'''BACK TO EXOTICS''']]</center></big> | ||
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+ | <big><center>[[Exotics_-_Avian_Reproductive_Anatomy_and_Physiology_-_Anatomy_%26_Physiology|'''BACK TO AVIAN REPRODUCTIVE ANATOMY & PHYSIOLOGY''']]</center></big> | ||
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+ | <big><center>[[Exotics_-_Reproduction_in_the_Male_Avian_-_Anatomy_%26_Physiology|'''BACK TO MALE AVIAN REPRODUCTIVE ANATOMY & PHYSIOLOGY''']]</center></big> | ||
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+ | = Introduction = | ||
Paired reproductive tracts lie along the dorsal body wall. Each tract consists of a testis, a rudimentary epididymis and a highly convoluted deferent duct running alongside the ureter. The testes are connected to the body wall by a mesochorium. This peritoneal fold serves as an attachment for the testes and also a conduit for nerves and blood vessels. | Paired reproductive tracts lie along the dorsal body wall. Each tract consists of a testis, a rudimentary epididymis and a highly convoluted deferent duct running alongside the ureter. The testes are connected to the body wall by a mesochorium. This peritoneal fold serves as an attachment for the testes and also a conduit for nerves and blood vessels. | ||
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− | + | = Testes = | |
* Bean-shaped, paired | * Bean-shaped, paired | ||
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* Left tends to be larger than right in immature birds. | * Left tends to be larger than right in immature birds. | ||
− | * | + | * Dimentions increase rapidly with sexual activity. |
* In the non-breeding season, testes shrink to almost nothing and become hard to visualize. | * In the non-breeding season, testes shrink to almost nothing and become hard to visualize. | ||
* Dormant testes light brown/yellow in colour, turn white when sexually active. | * Dormant testes light brown/yellow in colour, turn white when sexually active. | ||
** In some psittacine species, immature or dormant testes may appear black due to melanocytes located in the interstitium. | ** In some psittacine species, immature or dormant testes may appear black due to melanocytes located in the interstitium. | ||
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+ | * '''Semniferous tubules''' produce '''sperm''' from the epithelium. | ||
+ | * Interstitial '''Leydig cells''' lie between semniferous tubules. | ||
* Tunical Albiguinea thinner than in mammals. | * Tunical Albiguinea thinner than in mammals. | ||
* '''No Pampiniform plexus'''. | * '''No Pampiniform plexus'''. | ||
− | + | * '''Epididymis is small and can be considered absent'''. '''Sperm maturation occurs in the Vas Deferens'''. | |
− | + | * Vas Deferens closely associated with the Ureter in the dorsomedial midline coelom, distinguished by its zig-zag appearance. | |
− | * | + | * Vas Deferens enters dorsal wall of the cloacal urodeum. |
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** Straightens and abruptly widens at ats junction with the cloaca. | ** Straightens and abruptly widens at ats junction with the cloaca. | ||
− | *** Structure known as the | + | *** Structure known as the receptacle. |
*** Receptacle appears bean-shaped when engorged with semen. | *** Receptacle appears bean-shaped when engorged with semen. | ||
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− | + | ---- | |
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+ | = Phallus = | ||
* Most birds lack a true phallus. | * Most birds lack a true phallus. | ||
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− | + | == Absence of Phallus == | |
* Psittacines, Passerines, Pidgeons and birds of prey all have no phallus. | * Psittacines, Passerines, Pidgeons and birds of prey all have no phallus. | ||
− | * Copulate by transferring semen from the everted [[ | + | * Copulate by transferring semen from the everted [[The_Avian_Vent_and_Cloaca_-_Anatomy_%26_Physiology#The_Cloaca|Cloaca]] directly into the female [[Exotics_-_Anatomy_of_the_Female_Reproductive_System_-_Anatomy_%26_Physiology#Oviduct|oviduct]]. |
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− | + | == Non-Protrusible Phallus == | |
* Rudimentary non-protrusible phallus is seen in male Turkeys and Chickens. | * Rudimentary non-protrusible phallus is seen in male Turkeys and Chickens. | ||
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* Consists of a small medial tubercle intimately associated on each side with lymphatic folds and vessels. | * Consists of a small medial tubercle intimately associated on each side with lymphatic folds and vessels. | ||
* When erect with lymph, the phallus develops a median groove. | * When erect with lymph, the phallus develops a median groove. | ||
− | ** Median groove permits passage of ejaculate down into the everted female [[ | + | ** Median groove permits passage of ejaculate down into the everted female [[Exotics_-_Anatomy_of_the_Female_Reproductive_System_-_Anatomy_%26_Physiology#Oviduct|oviduct]]. |
− | + | == Protrusible Phallus == | |
* Ratites and Anseriformes | * Ratites and Anseriformes | ||
− | * Elongated, capable of true intromission into the female | + | * Elongated, capable of true intromission into the female cloaca. |
− | * Distal end lies enclosed in a cavity on the floor of the | + | * Distal end lies enclosed in a cavity on the floor of the cloaca and becomes engorged with lymphatic fluid. |
** Anseriformes have a curved, fibrous phallus that conveys semen via a spiral groove. | ** Anseriformes have a curved, fibrous phallus that conveys semen via a spiral groove. | ||
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− | + | = Accessory Sex Organs = | |
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− | [[ | + | * No [[Male_Reproductive_Tract_-Accessory_Sex_Glands_-_Anatomy_%26_Physiology|accessory sex glands]] that are seen in mammals. |
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Revision as of 09:58, 22 July 2008
Introduction
Paired reproductive tracts lie along the dorsal body wall. Each tract consists of a testis, a rudimentary epididymis and a highly convoluted deferent duct running alongside the ureter. The testes are connected to the body wall by a mesochorium. This peritoneal fold serves as an attachment for the testes and also a conduit for nerves and blood vessels.
Testes
- Bean-shaped, paired
- Lie near the cranial pole of the kidney
- Medially, they lie close to the aorta and caudal vena cava.
- Each testical suspended by a short mesochorium and surrounded medially by the abdominal air sac.
- Left tends to be larger than right in immature birds.
- Dimentions increase rapidly with sexual activity.
- In the non-breeding season, testes shrink to almost nothing and become hard to visualize.
- Dormant testes light brown/yellow in colour, turn white when sexually active.
- In some psittacine species, immature or dormant testes may appear black due to melanocytes located in the interstitium.
- Semniferous tubules produce sperm from the epithelium.
- Interstitial Leydig cells lie between semniferous tubules.
- Tunical Albiguinea thinner than in mammals.
- No Pampiniform plexus.
- Epididymis is small and can be considered absent. Sperm maturation occurs in the Vas Deferens.
- Vas Deferens closely associated with the Ureter in the dorsomedial midline coelom, distinguished by its zig-zag appearance.
- Vas Deferens enters dorsal wall of the cloacal urodeum.
- Straightens and abruptly widens at ats junction with the cloaca.
- Structure known as the receptacle.
- Receptacle appears bean-shaped when engorged with semen.
- Straightens and abruptly widens at ats junction with the cloaca.
Phallus
- Most birds lack a true phallus.
- Analogue of the mammalian penis.
- Consists of a small median tubercle flanked by a pair of large, lateral phallic bodies.
- When present, the avian phallus is soley reproductive and becomes engorged by lymph fluid instead of blood during erection.
- Owing to the lack of accessory sex glands, avian semen has low volume.
- Some lymph may contribute to the seminal fluid.
- Sperm remains viable in the female tract for much longer than in mammals.
- May survive for 5-6 days.
Absence of Phallus
- Psittacines, Passerines, Pidgeons and birds of prey all have no phallus.
- Copulate by transferring semen from the everted Cloaca directly into the female oviduct.
Non-Protrusible Phallus
- Rudimentary non-protrusible phallus is seen in male Turkeys and Chickens.
- Lies on the ventral lip of the vent.
- Consists of a small medial tubercle intimately associated on each side with lymphatic folds and vessels.
- When erect with lymph, the phallus develops a median groove.
- Median groove permits passage of ejaculate down into the everted female oviduct.
Protrusible Phallus
- Ratites and Anseriformes
- Elongated, capable of true intromission into the female cloaca.
- Distal end lies enclosed in a cavity on the floor of the cloaca and becomes engorged with lymphatic fluid.
- Anseriformes have a curved, fibrous phallus that conveys semen via a spiral groove.
Accessory Sex Organs
- No accessory sex glands that are seen in mammals.