HUBS1404 Lecture Notes - Lecture 17: Pancreatic Juice, Paneth Cell, Goblet Cell
19 Jul 2018
School
Department
Course
Professor
Document Summary
Ileum: completion of chemical digestion, bile and pancreatic fluid entry, chyme mixing/ propulsion, absorption. Length ~7m: circular folds (plicae, villi- enterocytes (absorptive epithelia, each vili has an arteriole, a venous drainage vessel and a lymphatic vessel, microvilli - brush boarder - bb enzymes (complete digestion of chos and proteins) Length x folds x villi x microvilli = surface area (~200 m2: duodenum = most active absorption (proximal part of si) Si tunic modifications - secretions: goblet cells - mucous, increases distally. Slightly alkaline, isotonic with plasma: enzyme poor (enzymes attached to bb, mucous secreted by goblet cells and duodenal glands, enteroendocrine cells - secretin ckk (enterogastrones) Intraepithelial lymphocytes - release cytokines to kill infected cells: paneth cells - antimicrobials (defensins and lysosomes, stem cells - migration -apoptosis - villi tips (relaced every 2-4 days) Bile from liver: 3-6h journey across huge (~200m2) sa to allow water and nutrient absorption.
