vertebrate digestive system histology

The vertebrate digestive tract, like that of invertebrates, is highly specialized in both structure and function for the digestion of a wide array of food. The basic components of the gut tube include the buccal cavity, pharynx, esophagus, stomach, small intestine, large intestine, rectum, anus/cloaca. A few vertebrates lack a stomach (cyclostomes, lungfish) but in most it functions for storage and acidic/enyzmatic digestion.

it is modified for fermentation in ruminant and pseudoruminant mammals. Absorbtion is the primary function of the small intestine in higher vertebrates, although some absorbtion occurs in the stomach and large intestine. There are three important glandular systems in vertebrate digestive system.

1-The salivary glands
2-The liver, gallbladder and bile duct
3-Pancreas and pancreatic duct
The liver is a large organ that secretes bile fluid.
Some mammals lack a gallbladder. Cephalochordates and cyclostomes lack a pancreas.

The large intestine of mammals is generally more developed than other vertebrates, is responsible for water reabsorbtion and formation of feces. Bacterial action in the hindgut can ferment cellulose and can synthesize vitamins. source: histology