Mammalian Digestive Systems


Biology 453

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Cat Salivary Glands
Submandibular gland is the exposed triangular shape in the lower left & the parotid gland is at the right.

The massester muscle of the jaw is at the lower left, the submandibular gland is the oval at the lower right & above is part of the large, whitish parotid gland.

Cat "Mesenteries"
The greater omentum is a double wall of peritoneal membrane & may act as a fat storage organ.

Cat liver & greater omentum. Find the gall bladder in a pocket of liver tissue.

Another view of the greater omentum & the spleen which is really a cardiovascular organ.

The falciform ligament is a remnant of the umbilical cord & attaches between the major right & left lobes of the liver. The falciform then attaches to the diaphragm (cut here). Heart & lungs are also visible.


Cat: Abdominal Viscera
View of the liver & intestines after removal of greater omentum. Find the gall bladder between folds of the liver in the lower left.

Leakage from the small, dark green gall bladder, stains surrounding portions of the liver green too.

The cat cecum ends in the small side-pocket at the lower left, the colon extends upward & to the right.

Pancreatic tissue in a cat extends in two thin sections, one section is beside the small intestine (stained, in part, in this view with some yellow latex) & the other passes underneath the greater omentum towards the right.

Stomach Exterior

Stomach Rugae

Pyloric region of Stomach - with duodenum

Duodenum (first section of small intestine) with part of pancreas.

Ileocolic Junction has a sphincter controlling movement of materials from the small intestine into the colon.

The cat's cecum is at the right & the colon extends in off to the left. The cecum of a cat is very small compared to that of a rabbit below.


Stomach - with part of esophagus at the top & part of the small intestine & pancreas at the left. The stomach is large because green (moist) fecal pellets are reingested & stored here for a repeat of the digestive activity.

The rabbit cecum is a large, sac-like structure that ends with small 'appendix" on the left.

Small section of intestines - left - large intestine, middle - small intestine, right - cecum


Ruminants (Cow/Sheep)
Ruminant Stomach, all 4 chambers visible, rumen is the largest to the far left. Moving right, part of the esophagus is present above the reticulum, next is the omasum, abomasum & part of the small intestine is folded back towards the left (above the section of the esophagus.

Rumen closeup - bacterial fermenation of cellulose occurs here.

Reticulum closeup - undigested plant matter is compressed & then regurgiated.

Omasum closeup - water is reabsorbed from from the digested fluid that passes through the reticulum

Abomasum closeup - release pepsin & acids for typical protein digestion.

Abomasum (right) ends at the pyloric sphincter (center) leading into the small intestine (left).

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