Anatomy & Physiology 12 - Digestion Vocabulary #1

Anus

Posterior opening of the digestive tract protected by the anal sphincter

Bile

Secretion of the liver that is temporarily stored & concentrated in the gallbladder before being released into the small intestine where it emulsifies fat

Capillary

Microscopic blood vessel connecting arterioles to venules; exchange of substances between blood and tissue fluid occur across their thin walls

Cardiac Sphincter

Muscular ring along the gastro-intestinal tract, located where the esophagus meets the stomach (near the heart); This sphincter relaxes to allow a food bolus to enter the stomach

Chemical digestion

Hydrolytic reactions that reduce food molecules to monomers by enzymatic activity; occurs in the mouth, stomach, and duodenum

Digestive Enzyme

Hydrolytic enzyme that chemically breaks food molecules into monomers; can be found in saliva, gastric juice, intestinal juice, and pancreatic juice

Duodenum

First portion of the small intestine where the majority of digestive activity takes place; food leaves the stomach through the pyloric sphincter to this organ where bile from the gallbladder & pancreatic juices are released; its walls are specialized and make intestinal juices

Emulsification of fat

Breaking up of fat globules into smaller droplets by the action of bile salts or any other emulsifier

Epiglottis

Structure that covers the glottis and closes off the air tract during the process of swallowing

Esophagus

Muscular tube for moving swallowed food from the pharynx to the stomach

Gallbladder

Thin-walled storage sac attached to the underside of the liver that stores bile produced by the liver; when its release is signalled, bile is released into the duodenum and emulsifies fats to increase the efficiency of lipase

Gastric juice

Digestive secretion produced by the stomach that is released as an action of the hormone, gastrin; it contains HCl, pepsinogen (pepsin precursor), and mucus (mostly water)

Hydrochloric acid (HCl)

Causes the stomach to have a high pH of about 2 which is beneficial because it kills most bacteria in food; it does not digest food but it breaks down the connective tissue in meat and activates pepsin

Insulin

Hormone secreted by the pancreas that lowers the blood glucose level by promoting the uptake of glucose by cells and the conversion of glucose into glycogen by the liver and skeletal muscles

Intestinal juice (enzymes & mucus)

Digestive secretion of the small intestine; contains a variety of enzymes that complete the chemical digestion of food; includes disaccaridases, peptides, nucleases, and water

Lacteals

Lymphatic vessel in an intestinal villus; it aids in the absorption of lipids

Large intestine (colon)

Includes the cecum, colon, rectum, and anal canal; shorter than but wider than the small intestine; absorbs water, salt, and some vitamins; stores indigestible material until it is eliminated by the anus

Lipase

Lipid-digesting enzyme that is produced by the pancreas and enters the duodenum as a component of pancreatic juice; the products of its activity are fatty acids and glycerol and its efficiency is increased by the activity of bile

Liver

Largest inner organ of the body located posterior to the diaphragm; functions include: the production of bile, the conversion of ammonia into urea, storage of glucose as glycogen, and production of globulins

Maltase

Enzyme produced in small intestine that breaks down maltose to two glucose molecules