This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Lecture Notes Bio 109, Fall 2010, Dr. Catherine Loudon Lecture 24 – 11/22/10 – Digestion 1) Recorded lecture (movie file link posted on EEE) 2) Motility, continued a) Peristalsis moves food along (Fig. 21-5) b) Segmental contractions mix chyme inside GI tract (Fig. 21-5) 3) Fluid input and output to digestive tract (Fig. 21-1) contrasted with fluid exchange between body and environment (Fig. 20-2) 4) Secretion a) First ions are transported, then water follows b) Different transporters in apical vs. basolateral membranes of transporting epithelial cells i) Transporters: ATPases, symporters, antiporters, channels c) HCl secretion by parietal cells of stomach (Fig. 21-6) d) NaHCO3 secretion into duodenum by pancreas (involvement of CFTR channel) (Fig. 21-8) i) Importance of pH in digestive enzyme function e) Pancreas – endocrine and exocrine gland (Fig. 21-7) f) NaCl solution secretion by crypt cells in small intestine and colon (Fig. 21-9, Fig. 21-3) 5) List of secretions a) Saliva (salivary glands) b) HCl solution (stomach cells) c) Digestive enzymes d) NaHCO3 solution (pancreas, small intestine) e) NaCl solution (crypt cells of small intestine, colon) f) Mucus (salivary glands, stomach, intestine) – glycoproteins (mucins) form protective coating g) Bile synthesized by liver (bile salts solubilize fats, bilirubin, cholesterol, some drugs) 6) Bile stored in gallbladder (Fig. 21-10), released into small intestine when gall bladder contracts 7) Primary site of nutrient absorption – endothelial cells of small intestine (Fig. 21-13) a) Blood vessels (capillaries) and lacteals extend into villi b) Individual cells have microvilli (brush border) 8) Digestion and absorption of carbohydrates (e.g. starch, glycogen, Digestion and absorption of carbohydrates (e....
View Full Document
This note was uploaded on 12/01/2010 for the course BIO SCI Bio Sci E1 taught by Professor Catherineloudin during the Spring '10 term at UC Irvine.
- Spring '10