EXMD 509 Lecture Notes - Lecture 4: Blood Vessel, Cotransporter, Sucrase

• School: McGill University
• Department: Experimental Medicine
• Course: EXMD 509
• Professor: Gary Wild

Document Summary

The intestinal surface area is enhanced by finger-like villi. Ratio of height of villus to depth of crypt is 3:1. Cells in the crypt do not absorb but can secrete: they become fully competent and differentiated at the tip-villus junction, zone of differentiation. The process of cell less from villus = apoptosis. The primary absorptive processes on the apical side nutrient absorption. Na enters the cell via concentration gradient. Sglt gene in a variety of states: responsible for na and glucose transport. Glut2: glucose and galactose share the same transporter. In the large intestine, there is a system that is different from the small intestine. Instead there is na and cl going through the channel. Unsure of how cl is extruded but it exits the basolateral domain. Colon has no nutrient absorption whatsoever (water only) The major osmotic problem is to absorb and reabsorb virtually all of the na, cl, hco3 and water.