HUBS192 Lecture Notes - Lecture 30: Intestinal Epithelium, Tight Junction, Extracellular Fluid

• School: University of Otago
• Department: Human Body Systems
• Course: HUBS192
• Professor: Greg Jones

Document Summary

Absorption confined to small intestine, though there are diff. parts of the intestine that are involved in absorbing different types of material, so it"s important to know what is absorbed where at the small intestine. Movement of substances from small intestine lumen; across the intestinal lining into the interstitial fluid, then into blood/lymph depending on what"s been absorbed, to be distributed around the body. Have to set up movement of these substances (unidirectional movement) out of lumen, don"t want nutrients moving in and out, just want unidirectional movement into the interstitial fluid. Only certain things are extracted from lumen, epithelial cells need to identify what the body needs and what they"re going to transport across intestinal lining. Epithelial cell layer: serve as barrier, selectively get the things it needs from the lumen into interstitial fluid. Little amount of absorption in mouth, oesophagus and stomach (if they are lipid soluble substances, which can freely diffuse into cell, don"t need transporters)