GASTRIC GLAND
It has 4 special types of cells
- Chief cells or zymogen cells
¤ secrete pepsinogen
¤ abundant in fundus of gastric gland
• Parietal or oxyntic cells
¤ secrete HCL and intrinsic factor of castle
¤ abundant in isthmus
• mucous cells
¤ secrete mucus
¤ abundant in neck
• neuroendocrine cells
¤ G-cells : gastrin ;S-cells : somatostatin;enterochromaffin like cell : histamine
¤ present more deep in fundus
BRUNNER'S GLAND
• characteristic of upper duodenum
• secrete mucus
PANETH CELLS
• Charecteristic of small intestine
• granular,secretory,eosinophilic,exocrine cell
• present deeply in crypts and unlike other cells dont migrate to surface of small intestine mucosa
• life span is 28 days
• contains zinc,lysosome,rough endoplasmic reticulum
• secrete lysozyme,cryptidin,tnf a,phospholipase a2,antichymotrypsin
PAYERS PATCHES
• characteristic of ileum
• aggregates of lymphoid nodules
SPECIAL CELLS OF SMALL INTESTINE
• mucosa of small intestine invaginates to form crypts of luberkuhn and evaginates yo form villi
• in villi :
1) goblet cells - secrete mucus and provides lubrication and barrier to infection
2) M cells (microfolds) - covers underlying lymphocytes,process antigens and present it to underlying lymphocytes
3) lymphocytes
• in crypts :
1) stem cells - replaces old dying cells in mucosa
2) paneth cells
3) neuroendocrine cells/APUD cells
NERVE INERVATION OF GIT
1) Auerbachs plexus/myentric
• between outer longitudinal muscle and inner circular muscle
• has motor control over git
2) Meissners plexus
• between circular muscle layer and mucosa
• has secretion control
