BIOL 103 Chapter Notes - Chapter 14: Binge Eating, Cholecystokinin, Energy Economics
Document Summary
Contains the lumen which is the space within the tube. 4 layers: mucosa: innermost layer, mucous membrane in contact with the lumen. Mucosa adaptations increases surface area to facilitate absorption. Villi: microscopic projections containing blood and lacteal capillaries; increases surface area. Microvilli: cytoplasmic projections of epithelial cells of the villi: submucosa: layer of connective tissue containing blood vessels, lymph vessels, nerves, muscularis: two or three layers of smooth muscle, responsible for movement, motility, serosa: outermost layer. Sphincters: thick muscular rings that separate some of the organs. Accessory organs: outside of the gi tract: salivary glands, liver, gallbladder, pancreas, aids digestion and absorption. Pancreas: exocrine functions, secretes digestive enzymes and sodium bicarbonate (nahco3, role of bicarbonate: neutralized stomach acids, digestive enzymes include, proteases: trypsin, chymotrypsin, and carboxypeptidase, pancreatic amylase: digests starch, lipase: digests lipids. The bile produced by the liver emulsifies lipids and go to the gallbladder. Hepatic portal system: drains blood from the digestive tract to the liver.
