Difference between revisions of "Avian Vent and Cloaca - Anatomy & Physiology"
| Line 1: | Line 1: | ||
| − | == | + | ==Overview== |
| + | |||
| + | The hindgut of the avian digestive system terminates in the '''cloaca'''. The external opening through which faecal matter and uric acid is excreted is called the '''vent'''. The shape of the vent varies depending on species. | ||
| + | [[Image:Avian Cloaca Diagram.jpg|thumb|right|250px|Avian Cloaca Diagram - Copyright RVC 2008]] | ||
| − | |||
| − | |||
==The Cloaca== | ==The Cloaca== | ||
| − | + | The '''[[Colon - Anatomy & Physiology|Colon]]''', '''[[Ureters - Anatomy & Physiology|ureters]]''' and '''deferent ducts'''/'''left [[Exotics - Anatomy of the Female Reproductive System & Physiology of Egg Formation - Anatomy & Physiology#Oviduct|oviduct]]''' enter at various levels. It can be divided into the '''coprodeum''', '''urodeum''' and '''proctodeum''' by complete annular folds. Some urinary excretions arriving in the cloaca become incorporated with the ingesta and move in a retrograde fashion to the [[Caecum - Anatomy & Physiology|caeca]], increasing the absorption of water and electrolytes from the urinary waste. | |
| − | + | The '''coprodeum''' is the most cranial division of the cloaca. It is the continuation of the colon where faeces are stored. It is bounded by the '''coprourodeal fold'''. It can be stretched by the faecal pressure so the central opening is everted through the vent. | |
| − | + | The '''urodeum''' is the middle part of the cloaca. It is caudal to the '''proctodeum fold'''. It is the uteric opening in the dorsolateral wall above the papilla of the deferent duct/[[Exotics - Anatomy of the Female Reproductive System & Physiology of Egg Formation - Anatomy & Physiology#Oviduct|oviduct]] opening. | |
| − | + | [[Image:Bursa of Fabricus.jpg|thumb|right|250px|Bursa of Fabricus - Copyright Nottingham 2008]] | |
| − | |||
| − | |||
| − | |||
| − | + | The '''proctodeum''' is the caudal segment. It is short and ends at the vent. The opening in the dorsal wall leads to the cloacal '''bursa of Fabricus'''. | |
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
==The Vent== | ==The Vent== | ||
| − | + | The vent is a horizontal slit. It is the [[Exotics - Reproductive Tract Anatomy- Anatomy & Physiology#Phallus|phallus]] of males on the internal surface of the ventral lip. During insemination, the vent is inverted. | |
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
==Species Differences== | ==Species Differences== | ||
| − | + | '''Galliformes''' (turkeys and chickens) can move urates from the urinary tract into the [[Colon - Anatomy & Physiology|colon]] and [[Caecum - Anatomy & Physiology|caeca]] where ammonia is released for protein synthesis. A small membrane covers the opening of the [[Exotics - Anatomy of the Female Reproductive System & Physiology of Egg Formation - Anatomy & Physiology#Oviduct|oviduct]] into the cloaca in '''ducks''', '''geese''' and '''swans''' until sexual maturity. | |
| − | + | ==Links== | |
| − | |||
| − | == | ||
| − | |||
| − | |||
| − | + | '''Test yourself with the [[The Avian Alimentary Tract - Anatomy & Physiology - Flashcards|Avian Alimentary Tract Flashcards]]''' | |
| − | [[Bursa of Fabricius - Anatomy & Physiology|Bursa of Fabricus]] | + | '''Click here for [[Avian Vent and Cloaca - Histology|avian histology]]''' |
| + | '''Click here for information on the [[Bursa of Fabricius - Anatomy & Physiology|Bursa of Fabricus]]''' | ||
[[Category:Avian Alimentary System - Anatomy & Physiology]] | [[Category:Avian Alimentary System - Anatomy & Physiology]] | ||
| − | [[Category:To Do - | + | [[Category:To Do - AimeeHicks]] |
Revision as of 08:49, 10 September 2010
Overview
The hindgut of the avian digestive system terminates in the cloaca. The external opening through which faecal matter and uric acid is excreted is called the vent. The shape of the vent varies depending on species.
The Cloaca
The Colon, ureters and deferent ducts/left oviduct enter at various levels. It can be divided into the coprodeum, urodeum and proctodeum by complete annular folds. Some urinary excretions arriving in the cloaca become incorporated with the ingesta and move in a retrograde fashion to the caeca, increasing the absorption of water and electrolytes from the urinary waste.
The coprodeum is the most cranial division of the cloaca. It is the continuation of the colon where faeces are stored. It is bounded by the coprourodeal fold. It can be stretched by the faecal pressure so the central opening is everted through the vent.
The urodeum is the middle part of the cloaca. It is caudal to the proctodeum fold. It is the uteric opening in the dorsolateral wall above the papilla of the deferent duct/oviduct opening.
The proctodeum is the caudal segment. It is short and ends at the vent. The opening in the dorsal wall leads to the cloacal bursa of Fabricus.
The Vent
The vent is a horizontal slit. It is the phallus of males on the internal surface of the ventral lip. During insemination, the vent is inverted.
Species Differences
Galliformes (turkeys and chickens) can move urates from the urinary tract into the colon and caeca where ammonia is released for protein synthesis. A small membrane covers the opening of the oviduct into the cloaca in ducks, geese and swans until sexual maturity.
Links
Test yourself with the Avian Alimentary Tract Flashcards
Click here for avian histology Click here for information on the Bursa of Fabricus