This includes 4 major layers of alimentary canal structure (p. 848, 850), but does not include cell-level details. Chart shown in class is a nice summary. Also know the different hormonal controls (p. 854-855 and online). Also know the dietary source of the major nutrients and the most important vitamins and minerals. (No need to memorize all the steps of the Krebs cycle.) Also know how metabolism and weight are controlled. THIS LIST IS UNDER DEVELOPMENT AND MAY EXPAND Mechanical digestion: Breaking food into smaller pieces or detaching loose material to expose new surface for chemical digestion. Chemical digestion: Breaking down food ingredients chemically into smaller molecules that the body can absorb. Peristalasis: Rhythmic waves of muscular contraction that keep the digestive contents moving along. Lumen: Hollow interior of any organ. Mesentery: Double-walled extension of the serosa that connects internal organs to the dorsal body wall. Cardia: Region of stomach near esophagus, with thin walls. Fundus: Superior (cranial) end of stomach, where most HCl is secreted; serves as a center from which muscle fibers radiate. Pylorus: Lower half of stomach, lined with a thick mucosa whose glands secrete thick mucus and protein-digesting enzymes. Cardiac sphincter: Circular muscle band at entrance to stomach. Pyloric sphincter: Circular muscle band at exit from stomach to duodenum. Rugae: Longitudinal folds in the stomach lining. Chief cells: The most numerous cells in stomach lining, secreting protein-digesting enzymes. Parietal cells: Cells in the stomach lining that secrete hydrochloric acid, mostly in the fundus region. Greater omentum: Double fold of mesentery that drapes over intestines like an apron. Bile: Fluid secreted by the liver, containing bile salts and pigments. Acinar glands: Flask-shaped glands in the pancreas, with pyramidal cells that secrete digestive enzymes. Islets of Langerhans: Small clumps of cells in the pancreas that secrete the hormones insulin and glucagon. Gall bladder: Pouch that stores liver secretions (bile) until they are needed. Emulsification: Coating of small fat droplets with soap-like molecules (like bile salts) to keep them from coalescing into big fat droplets. Jejunum: Portion of small intestine where chemical digestion is completed. Ileum: Portion of small intestine where digested products are absorbed. Villi: Finger-like projections of the intestinal surface. Microvilli (brush border): Minute, finger-like folds in the plasma membrane of intestinal cells, greatly increasing surface area; final steps of digestion are completed here. Goblet cells: Cells that secrete a protective mucus. Hepatic portal system: System of veins draining blood from the digestive organs into the liver. Gut: The tube-like structure, lined with endoderm, from which the alimentary canal develops. The pancreas, liver, lungs, and bladder originate as outgrowths from this tube. Stomodeum: The ectoderm-lined pouch that develops into the mouth. Anorexia nervosa: Self-starvation disorder in which misperception of one's body leads to a strong obsession to be thin and in control. Bulimia: Psychological disorder characterized by behavior of binge-eating followed by purging (often by self-induced vomiting). Kwashiorkor: Starvation that includes protein deprivation, tissue swelling (edema), and muscle wasting. Mumps: Inflammation of the salivary glands (especially the parotid gland). Gastric reflux (G.E.R.D.): Splashing of stomach contents into the lower esophagus, causing "heartburn" sensations. Barrett's esophagus: Alteration of the lower esophagus to resemble the cardia of the stomach due to repeated gastric reflux. Ulcer: An open, bleeding sore anywhere, but especially in the stomach or duodenum, where they are caused by Helicobacter pylori. Gallstones: Solid deposits in the gall bladder that may painfully block its opening. Pancreatitis: Painful inflammation of the pancreas, often following blockage of the bile duct by gallstones. Inflammatory Bowel Disease (incl. Crohn's disease and ulcerative colitis): Episodic inflammation of the intestinal lining, resulting from inability of TH17 cells to fight off normal bacteria, often causing painful scarring and ulcers. Mayo clinic web site. Celiac disease (sprue): Painful allergic reaction to wheat gluten, causing diarrhea, severe cramps, etc. Diarrhea: Loose or watery stools, resulting from inadequate removal of water by the colon. Glycogen: A long-chain polysaccharide that animals use as a storage form of glucose. Glycolysis: The breakdown of glucose to form pyruvate. Electron transport: A series of oxidation/reduction reactions that remove hydrogen atoms, finally reducing atmospheric oxygen to water. Chemiosmosis: A process, resulting from electron transport, that pumps hydrogen ions (protons) across the inner mitochondrial membrane, then uses these protons to power ATP synthesis as they leak back. Transamination: A chemical reaction that removes an amino group ( -NH2) from one compound and attaches it to another. |