MICROANATOMY

Detailed explanation-1: -Gastrin is a peptide hormone primarily responsible for enhancing gastric mucosal growth, gastric motility, and secretion of hydrochloric acid (HCl) into the stomach. It is present in G cells of the gastric antrum and duodenum.

Detailed explanation-2: -The GI hormones that regulate gut mucosal growth positively or negatively include gastrin, CCK, secretin, somatostatin, ghrelin, bombesin, and gastrin-releasing peptide (GRP).

Detailed explanation-3: -The stomach is the primary site of gastrin production with some D-cells also populating the duodenum. Somatostatin and histamine are also produced in the stomach by enterochromaffin-like (ECL) cells, which is an enteroendocrine cell subtype.

Detailed explanation-4: -Gastrin stimulates the secretion of gastric and pancreatic juice, insulin and glucagon, motility of the stomach and intestine, increases the tone of the lower esophageal sphincter and has a trophic effect on the mucous membrane of the digestive tract.

Detailed explanation-5: -Gastrointestinal (GI) hormones act in concert with the nervous system to regulate exocrine and endocrine GI secretion, cell proliferation, differentiation, and motility. The GI tract produces many different peptide hormones and GI-active neuropeptides, some of which are listed in Tables 1 and 2, respectively.