Function: digestion of food and absorption of the products of digestion.
Function: transport of substances from lumen of the intestine to the circulatory system, synthesis of the glycoprotein enzymes needed for terminal digestion and absorption.
Function: unicellular mucin-secreting glands.
Location: in the bases of the intestinal glands (crypts).
Function: their secretory granules contain the antibacterial enzyme lysozyme, other glycoproteins and zinc, play a role in regulating the normal bacterial flora of small intestine.
Location: predominantly in the lower portion of the intestinal glands (crypts).
Function: release of numerous hormones and hormone-like secretions. The most active are: cholecystokinin, secretin and gastric inhibitory peptide those increase pancreatic and gallbladder activity and inhibit gastric secretory function and motility.
Function: immature enterocytes and goblet cells that are still capable of cell division.
Function: facilitates the outflow of the intestinal gland secretion.
Composition: moderately dense irregular connective tissue, blood vessels, lymphatic vessels, nerve network and ganglion neurons (Meissner's plexus), white adipose tissue.
Location: in submucosa of duodenum.
Function: secretion of neutral and alkaline glicoproteins and bicarbonate ions (pH 8.1 - 9.3), protection the proximal small intestine by neutralizing the acid-containing chyme.
Composition: branched tubuloalveolar glands with protein-secreting and mucus-secreting cells.
Composition: Two layers of smooth muscle (inner - circular, outer - longitudinal), nerve network and ganglion neurons (Auerbach's plexus).
Composition: simple squamous epithelium - mesothelium, small amount of loose connective tissue, white adipose tissue, large blood vessels, lymphatic vessels, nerve trunks.