Difference between revisions of "Avian Intestines - Anatomy & Physiology"

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<big><center>[[Avian Digestive Tract - Anatomy & Physiology|'''BACK TO THE AVIAN DIGESTIVE TRACT - ANATOMY & PHYSIOLOGY''']]</center></big>
 
<big><center>[[Avian Digestive Tract - Anatomy & Physiology|'''BACK TO THE AVIAN DIGESTIVE TRACT - ANATOMY & PHYSIOLOGY''']]</center></big>
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==Structure==
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*The inestines occupy the caudal part of the body
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*Contacts the reproductive organs and [[The Gizzard - Anamtomy & Physiology|gizzard]]
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*The small intestine is long and relatively uniform in shape and size
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*There is no demarcation between the [[Jejunum - Anatomy & Physiology|jejunum]] and the [[Ileum - Anatomy & Physiology|ileum]]
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*The [[Duodenum - Anatomy & Physiology|duodenum]] passes caudally over the gizzard then loops back towards the stomach where it joins the [[Jejunum - Anatomy & Physiology|jejunum]]
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**Arises from the right dorsal aspect of the [[Gizzard - Anatomy & Physiology]]
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**Loop lies ventral on the abdominal floor
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**The pancreas lies within the loops
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**3 pancreatic ducts and one bile duct enter the caudal [[Duodenum - Anatomy & Physiology|duodenum]] at a common papila
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*[[Jejunum - Anatomy & Physiology|Jejunum]]
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**Loose coils around the mesentery
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**Thin walls so content appears green
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**Suspended from the dorsal wall of the abdomen by the mesentery
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*[[Ileum - Anatomy & Physiology|Ileum]]
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**Begins opposite the apices of the caeca or at the vitelline diverticula
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**Suspended from the dorsal wall of the abdomen by the mesentery 
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*A short [[Colon - Anatomy & Physiology|colon]]
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**The colon lies ventral to the synasacrum and opens into the cloaca
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**Runs ventral to the vertebrae
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**Terminates in the coprodeum
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*2 caeca from the ileocaecal junction run with the ileum caudally
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**Blind sacs about 16-18cm long
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**Extend towards the liver then fold back on themselves
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**Mesentery runs between the caeca then on towards the [[Ileum - Anatomy & Physiology|ileum]]
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**Often contain dark coloured material
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**3 parts of each caeca
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**Bacterial breakdown of cellulose occurs
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*Bile ducts and 3 pancreatic ducts
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==Vitelline Diverticula==
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*Small outgrowth on the [Jejunum - Anatomy & Physiology|jejunum]]
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*Former connection will yolk sac
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*Also called Meckel's diverticulum
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==Function==
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*See [[Small Intestine - Anatomy & Physiology|small intestine]]
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==Vasculature==
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*See [[Small Intestine - Anatomy & Physiology|small intestine]]
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==Innervation==
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*See [[Small Intestine - Anatomy & Physiology|small intestine]]
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==Lymphatics==
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*Patches of lymphoid nodules are present
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*Most abundant in the [[Duodenum - Anatomy & Physiology|duodenum]]
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==Histology==
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*Caeca
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**Serous coat has nerve plexuses
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**Columnar epithelium and goblet cells
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**Smooth muscle in folds at base
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**Caecal sphincter at proximal part containing a lot of lymphoid tissue (caecal tonsil)
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**Middle section has thin walls and appears green
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**The bulbous blind ends have thicker walls
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*See [[Small Intestine - Anatomy & Physiology|small intestine]]
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==Species Differences==
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*Duck and goose have several loops of 'U' shaped [[Jejunum - Anatomy & Physiology|jejunum]]
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*Pigeons have a circular mass of [[Jejunum - Anatomy & Physiology|jejunum]] with inner and outer turns
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*Long caeca in turkey and chicken
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*Pigeons and song birds have short caeca
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*Parrots do not have caeca
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==Links==

Revision as of 09:11, 15 July 2008

BACK TO THE AVIAN DIGESTIVE TRACT - ANATOMY & PHYSIOLOGY


Structure

  • The inestines occupy the caudal part of the body
  • Contacts the reproductive organs and gizzard
  • The small intestine is long and relatively uniform in shape and size
  • The duodenum passes caudally over the gizzard then loops back towards the stomach where it joins the jejunum
    • Arises from the right dorsal aspect of the Gizzard - Anatomy & Physiology
    • Loop lies ventral on the abdominal floor
    • The pancreas lies within the loops
    • 3 pancreatic ducts and one bile duct enter the caudal duodenum at a common papila
  • Jejunum
    • Loose coils around the mesentery
    • Thin walls so content appears green
    • Suspended from the dorsal wall of the abdomen by the mesentery
  • Ileum
    • Begins opposite the apices of the caeca or at the vitelline diverticula
    • Suspended from the dorsal wall of the abdomen by the mesentery
  • A short colon
    • The colon lies ventral to the synasacrum and opens into the cloaca
    • Runs ventral to the vertebrae
    • Terminates in the coprodeum
  • 2 caeca from the ileocaecal junction run with the ileum caudally
    • Blind sacs about 16-18cm long
    • Extend towards the liver then fold back on themselves
    • Mesentery runs between the caeca then on towards the ileum
    • Often contain dark coloured material
    • 3 parts of each caeca
    • Bacterial breakdown of cellulose occurs
  • Bile ducts and 3 pancreatic ducts


Vitelline Diverticula

  • Small outgrowth on the [Jejunum - Anatomy & Physiology|jejunum]]
  • Former connection will yolk sac
  • Also called Meckel's diverticulum


Function


Vasculature


Innervation


Lymphatics

  • Patches of lymphoid nodules are present


Histology

  • Caeca
    • Serous coat has nerve plexuses
    • Columnar epithelium and goblet cells
    • Smooth muscle in folds at base
    • Caecal sphincter at proximal part containing a lot of lymphoid tissue (caecal tonsil)
    • Middle section has thin walls and appears green
    • The bulbous blind ends have thicker walls


Species Differences

  • Duck and goose have several loops of 'U' shaped jejunum
  • Pigeons have a circular mass of jejunum with inner and outer turns
  • Long caeca in turkey and chicken
  • Pigeons and song birds have short caeca
  • Parrots do not have caeca

Links

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