01:119:115 Lecture Notes - Lecture 23: Portal Vein, Pancreatic Juice, Intestinal Villus
8 Jul 2015
School
Department
Course
Professor
Document Summary
Lecture 23: stomachs churning action (muscle contraction/relaxation) aids chemical digestion fig. 3: has very large surface area because it contains intestinal vili. Intestinal vili: finger-like projections of intestinal lining: have microvilli- folds of cytoplasm on exposed surface of epithelial cells b. Important in mechanical digestion of fats: does not contain digestive enzymes, also important in destruction of red blood cells (rbc) no longer functional, some pigments from rbc incorporated into bile. Digestion of specific nutrients figure 41. 12: carbohydrates, polysaccharides (starch, glycogen) disaccharides/smaller polysaccharides, starts in oral cavity by salivary amylase iii. In si, pancreatic enzymes secreted are inactive (trypsinogen, chymotrypsinogen, procarboxypeptides) Increases surface area that enzymes can work: pancreatic lipase glycerol, fatty acids, monoglycerides. Absorption of most nutrients occurs through villi in small intestine: few substances are small enough for absorption through stomach wall b. Inside intestinal villi are blood vessels and lacteal. Isoleucine: leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine ix.
