Changes

==Structure==

==Structure==

The '''inestines''' occupy the caudal part of the body. They contact the reproductive organs and the '''[[Gizzard - Anatomy & Physiology|gizzard]]'''. The '''small intestine''' is long and relatively uniform in shape and size. There is no demarcation between the '''[[Jejunum - Anatomy & Physiology|jejunum]]''' and the '''[[Ileum - Anatomy & Physiology|ileum]]'''.

The '''intestines''' occupy the caudal part of the body. They contact the reproductive organs and the '''[[Gizzard - Anatomy & Physiology|gizzard]]'''. The '''small intestine''' is long and relatively uniform in shape and size. There is no demarcation between the '''[[Jejunum - Anatomy & Physiology|jejunum]]''' and the '''[[Ileum - Anatomy & Physiology|ileum]]'''.

   

   

[[Image:Duodenum Avian Anatomy.jpg|thumb|right|250px|Anatomy of the Avian Duodenum and Pancreas - RVC 2008]]

[[Image:Duodenum Avian Anatomy.jpg|thumb|right|250px|Anatomy of the Avian Duodenum and Pancreas - RVC 2008]]

The '''[[Duodenum - Anatomy & Physiology|duodenum]]''' passes caudally over the '''[[Gizzard - Anatomy & Physiology|gizzard]]''' then loops back towards the stomach where it joins the '''[[Jejunum - Anatomy & Physiology|jejunum]]'''. It arises from the right dorsal aspect of the '''[[Gizzard - Anatomy & Physiology|gizzard]]'''. The loop lies ventral on the abdominal floor and the '''[[Pancreas - Anatomy & Physiology|pancreas]]''' lies within the loops. 3 '''pancreatic ducts''' and one '''bile duct''' enter the caudal '''[[Duodenum - Anatomy & Physiology|duodenum]]''' at a common papila.

The '''[[Duodenum - Anatomy & Physiology|duodenum]]''' passes caudally over the '''gizzard''' then loops back towards the stomach where it joins the '''jejunum'''. It arises from the right dorsal aspect of the '''gizzard'''. The loop lies ventral on the abdominal floor and the '''[[Pancreas - Anatomy & Physiology|pancreas]]''' lies within the loops. Three '''pancreatic ducts''' and one '''bile duct''' enter the caudal '''duodenum''' at a common papilla.

===[[Jejunum - Anatomy & Physiology|Jejunum]]===

===[[Jejunum - Anatomy & Physiology|Jejunum]]===

The short colon lies ventral to the '''synsacrum''' and opens into the '''[[Avian Vent and Cloaca - Anatomy & Physiology|cloaca]]'''. It runs ventral to the vertebrae and terminates in the '''coprodeum'''. Amino acids and glucose can be absorbed here.

The short colon lies ventral to the '''synsacrum''' and opens into the '''[[Avian Vent and Cloaca - Anatomy & Physiology|cloaca]]'''. It runs ventral to the vertebrae and terminates in the '''coprodeum'''. Amino acids and glucose can be absorbed here.

2 '''caeca''' from the '''ileocaecal junction''' run with the '''ileum''' caudally. They are blind sacs, about 16-18cm long. They extend towards the [[Avian Liver - Anatomy & Physiology|liver]] then fold back on themselves. The mesentery runs between the caeca then on towards the [[Ileum - Anatomy & Physiology|ileum]]. It often contains dark coloured material. There are 3 parts of each caeca. It is where the bacterial breakdown of cellulose occurs. Antiperistaltic movements transport chyme and the caeca are emptied a few times per day. Unlike mammals, there are no lacteals in the epithelium.

Two '''caeca''' from the '''ileocaecal junction''' run with the '''ileum''' caudally. They are blind sacs. They extend towards the [[Avian Liver - Anatomy & Physiology|liver]] then fold back on themselves. The mesentery runs between the caeca then on towards the ileum. It often contains dark coloured material. There are three parts of each caecum. It is where the bacterial breakdown of cellulose occurs. Antiperistaltic movements transport chyme and the caeca are emptied a few times per day. Unlike mammals, there are no lacteals in the epithelium.

===Vitelline Diverticula===

===Vitelline Diverticula===

[[Image:Vitelline Diverticula.jpg|thumb|right|250px|Vitelline Diverticula Anatomy- RVC 2008]]

[[Image:Vitelline Diverticula.jpg|thumb|right|250px|Vitelline Diverticula Anatomy- RVC 2008]]

The vitelline diverticula is a small outgrowth on the '''[[Jejunum - Anatomy & Physiology|jejunum]]'''. It is the former connection with the yolk sac. It is also called '''Meckel's diverticulum'''.

The vitelline diverticulum is a small outgrowth on the '''jejunum'''. It is the former connection with the yolk sac. It is also called '''Meckel's diverticulum'''.

==Function==

==Function==

==Histology==

==Histology==

The serous coat has nerve plexuses. There are columnar epithelium and goblet cells, with smooth muscle in folds at the base. The '''caecal sphincter''' at the proximal part contains a lot of lymphoid tissue. (caecal tonsil) The middle section has thin walls and appears green and the bulbous blind ends have thicker walls.  

The serous coat has nerve plexuses. There are columnar epithelium and goblet cells, with smooth muscle in folds at the base. The '''caecal sphincter''' at the proximal part contains a lot of lymphoid tissue (caecal tonsil). The middle section has thin walls and appears green and the bulbous blind ends have thicker walls.  

For more information, see: [[Small Intestine - Anatomy & Physiology#Histology|small intestine histology]]

For more information, see: [[Small Intestine - Anatomy & Physiology#Histology|small intestine histology]].

==Species Differences==

==Species Differences==

The '''duck''' and '''goose''' have several loops of 'U' shaped [[Jejunum - Anatomy & Physiology|jejunum]]. '''Pigeons''' have a circular mass of [[Jejunum - Anatomy & Physiology|jejunum]] with inner and outer turns. A long caeca is present in the '''turkey''' and '''chicken'''. '''Pigeons''' and song birds have a short caeca. '''Parrots''' do not have caeca. The dorsal and ventral lobes of the [[Pancreas - Anatomy & Physiology|pancreas]] are connected dorsally in '''poultry'''.

The '''duck''' and '''goose''' have several loops of 'U' shaped [[Jejunum - Anatomy & Physiology|jejunum]]. '''Pigeons''' have a circular mass of jejunum with inner and outer turns. Long caeca are present in the '''turkey''' and '''chicken'''. '''Pigeons''' and song birds have short caeca. '''Parrots''' do not have caeca. The dorsal and ventral lobes of the [[Pancreas - Anatomy & Physiology|pancreas]] are connected dorsally in '''poultry'''.

==Links==

==Links==

'''Click here for information on the [[:Category:Small Intestine - Anatomy & Physiology|Small Intestine - Anatomy & Physiology]]'''

'''Click here for information on the [[:Category:Small Intestine - Anatomy & Physiology|Small Intestine - Anatomy & Physiology]]'''

'''Click here for more information on the [[:Category:Large Intestine - Anatomy & Physiology|Large Intestine - Anatomy & Physiology]]'''

'''Click here for more information on the [[:Category:Large Intestine - Anatomy & Physiology|Large Intestine - Anatomy & Physiology]]'''

[[Category:Small Intestine - Anatomy & Physiology]]

[[Category:Small Intestine - Anatomy & Physiology]]

[[Category:Avian Alimentary System - Anatomy & Physiology]]

[[Category:Avian Alimentary System - Anatomy & Physiology]]

[[Category:To Do - Review]][[Category:To Do - AP Review]]

[[Category:A&P Done]]