Difference between revisions of "Avian Vent and Cloaca - Anatomy & Physiology"

Revision as of 16:32, 7 September 2010

Introduction

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.

Avian Cloaca Diagram - Copyright RVC 2008

The Cloaca

Colon, ureters and deferent ducts/left oviduct enter at various levels

Divided into 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
- Continuation of the colon where faeces are stored
- Bounded by the coprourodeal fold
- 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
- Caudal to the proctodeum fold
- Uteric opening in dorsolateral wall above the papilla of the deferent duct/oviduct opening

Bursa of Fabricus - Copyright Nottingham 2008

The proctodeum is the caudal segment
- Short
- Ends at the vent
- Opening in the dorsal wall leads to the cloacal bursa of Fabricus

The Vent

Horizontal slit

Phallus of males on internal surface of the ventral lip

During insemination the vent is inverted

Histology

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

Small memebrane coveres the opening of the oviduct into the cloaca in ducks, geese and swans until sexual maturity

Test yourself with the Avian Alimentary Tract flashcards

Avian Alimentary Tract Flashcards

Links

Bursa of Fabricus

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-{{OpenPagesTop}}
+==Introduction==
-==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 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|150px|Avian Cloaca Diagram - Copyright RVC 2008]]
 ==The Cloaca==
-The '''[[Colon - Anatomy & Physiology|colon]]''', '''[[Ureters - Anatomy & Physiology|ureters]]''' and '''deferent ducts'''/'''left [[Avian Female Reproductive System#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.
+*[[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
-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.
+*Divided into coprodeum, urodeum and proctodeum by complete annular folds
-The '''urodeum''' is the middle part of the cloaca. It is caudal to the '''proctodeum fold'''. It has the ureteric opening in  the dorsolateral wall above the papilla of the deferent duct/[[Avian Female Reproductive System#Oviduct|oviduct]] opening.
+*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
-[[Image:Bursa of Fabricus.jpg|thumb|right|250px|Bursa of Fabricus - Copyright Nottingham 2008]]
+*The coprodeum is the most cranial division of the cloaca
+**Continuation of the colon where faeces are stored
+**Bounded by the coprourodeal fold
+**Can be stretched by the faecal pressure so the central opening is everted through the vent
-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 urodeum is the middle part of the cloaca
+**Caudal to the proctodeum fold
+**Uteric opening in 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|150px|Bursa of Fabricus - Copyright Nottingham 2008]]
+*The proctodeum is the caudal segment
+**Short
+**Ends at the vent
+**Opening in the dorsal wall leads to the cloacal bursa of Fabricus
 ==The Vent==
-The vent is a horizontal slit. It has the [[Avian Male Reproductive Tract - Anatomy & Physiology#Phallus|phallus]] of males on the internal surface of the ventral lip. During insemination, the vent is inverted.
+*Horizontal slit
-==Histology==
+*[[Exotics - Reproductive Tract Anatomy- Anatomy & Physiology#Phallus|Phallus]] of males on internal surface of the ventral lip
-The avian vent and cloaca consist of columnar epithelium. Stratified squamous epithelium are present at the external opening of the vent and in the '''caudal proctodeum'''. There are broad folds of mucous membrane forming crypts, which branch near their base. Lymphoid tissue is present in the submucosa. The fold of mucous membrane covering the entrance to the bursa is composed of columnar epithelium, muscle, connective tissue and goblet cells. There are two layers of tunica muscularis; '''inner circular''' and '''outer longitudinal'''.
+*During insemination the vent is inverted
+==[[Avian Vent and Cloaca - Histology|Histology]]==
 ==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 [[Avian Female Reproductive System #Oviduct|oviduct]] into the cloaca in '''ducks''', '''geese''' and '''swans''' until sexual maturity.
+*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
+*Small memebrane coveres 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
+==Test yourself with the Avian Alimentary Tract flashcards==
+[[The Avian Alimentary Tract - Anatomy & Physiology - Flashcards|Avian Alimentary Tract Flashcards]]
 ==Links==
-'''Click here for information on the [[Bursa of Fabricius - Anatomy & Physiology|Bursa of Fabricus]]'''
+[[Bursa of Fabricius - Anatomy & Physiology|Bursa of Fabricus]]
-{{Template:Learning
-|flashcards = [[The Avian Alimentary Tract - Anatomy & Physiology - Flashcards|Avian Alimentary Tract]]
-}}
-==Webinars==
+[[Category:Alimentary System - Anatomy & Physiology]]
-<rss max="10" highlight="none">https://www.thewebinarvet.com/internal-medicine/webinars/feed</rss>
-[[Category:Avian Alimentary System - Anatomy & Physiology]]
-[[Category:Avian Reproduction]]
-[[Category:A&P Done]]