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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]] |
| + | **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 - Anatomy & Physiology|duodenum]] at a common papila |
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| + | *[[Jejunum - Anatomy & Physiology|Jejunum]] |
| + | **Loose coils around the mesentery |
| + | **Thin walls so content appears green |
| + | **Suspended from the dorsal wall of the abdomen by the mesentery |
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| + | *[[Ileum - Anatomy & Physiology|Ileum]] |
| + | **Begins opposite the apices of the caeca or at the vitelline diverticula |
| + | **Suspended from the dorsal wall of the abdomen by the mesentery |
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| + | *A short [[Colon - Anatomy & Physiology|colon]] |
| + | **The colon lies ventral to the synasacrum and opens into the cloaca |
| + | **Runs ventral to the vertebrae |
| + | **Terminates in the coprodeum |
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| + | *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 - Anatomy & Physiology|ileum]] |
| + | **Often contain dark coloured material |
| + | **3 parts of each caeca |
| + | **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 |
| + | **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 |
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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== |