PHYSIOL 1 Lecture Notes - Lecture 20: Ileocecal Valve, Descending Limb Of Loop Of Henle, Jejunum
Document Summary
Roughly 9l a day is the total amount absorbed by the intestine. 80% is reabsorbed from water contained in saliva, the digestive enzymes from the stomach and pancreas, bile and the secretions from the intestine. The remaining 20% comes from drinking and food. The amount of water absorbed in the intestine varies along its length. The ileum absorbs 38% and the large intestine absorbs 1. 5% The remaining 100ml is excreted in the feces. As molecules are absorbed, an osmotic gradient begins to build up across the intestinal epithelial cells. These cells develop a higher solute concentration inside lower water concentration. This causes water to flow into the cells by osmosis and down its concentration gradient. As the solutes move out of the cell into the circulation, water continues to follow by osmosis into the blood. The absorption of na+ occurs with the help of the na+/k+ pump located on the basal lateral surface of the intestinal cells.
