7 - Digestive System Flashcards
Breaking down of food into smaller particles and of macromolecules in food into smaller, absorbable molecules.
Digestion
Release of digestive enzymes and bile into the lumen of the GI tract.
Secretion
Movement of the molecules resulting from digestion from the GI tract lumen across a layer of epithelial cells and into the blood or lymph.
Absorption
Contractions of the smooth and some skeletal muscles in the GI tract wall that mix the luminal contents and propel them from mouth to anus.
Motility
Enzyme, found in saliva, begins polysaccharide digestion.
Amylase
Exocrine secretion of the stomach, kills bacteria, dissolves the particulate matter in food, activates pepsinogen into pepsins.
Hydrochloric acid
Exocrine secretion of the stomach, begins the digestion of proteins.
Pepsin
Exocrine secretion of the stomach, lubricates and protects the stomach.
Mucus
Exocrine secretion of the stomach, used for vitamin B12 absorption in the small intestine.
Extrinsic factor
Solution of partially digested protein/polysaccharide fragments/fat droplets/salt/water in the stomach/SI/LI.
Chyme
Performs most digestion
Small intestine
Secreted from exocrine portion of pancreas.
Pancreatic juice (i.e. contains bicarbonate and enzymes for digestion)
Secretion of the liver involved in digestion
Bile salts and bicarbonate
Gallbladder stores and concentrates bile between meals and contracts to secret it into the […] when needed
Duodenum
Connective tissue layer just beneath the mucose that contains a network of neurons plus blood and lymphatic vessels.
Submucosa