Ch 9 Digestive System

intracellular digestion

a part of metabolism that involves the oxidation of glucose and fatty acids for energy

extracellular digestion

nutrients are extracted from the food we eat and occurs within the lumen of the alimentary canal (GI tract)

sphincters

circular smooth muscles that sections off parts of the alimentary canal; they can contract to allow compartmentalization of function

digestion

the breakdown of food into its constituent organic molecules (turning carbs into monosaccharides, turning lipids into free fatty acids and glycerol, or turning proteins into amino acids)

mechanical digestion

the physical breakdown of large food particles into small ones

chemical digestion

the enzymatic cleavage of chemical bonds (such as peptide bonds in proteins or glycosidic bonds in carbs)

absorption

moving products of digestion from the GI tract into the blood stream to distribute to body’s tissues and cells

enteric nervous system

collection of 100 million neurons that govern the function of the gastrointestinal system

enteric nervous system

collection of neurons that triggers peristalsis

mastication

Scientific name for chewing

salivary amylase

an enzyme capable of hydrolyzing starch into smaller sugars

lipase

an enzyme that catalyzes the hydrolysis of lipids

epiglottis

cartilaginous structure that folds down to cover the larynx so food doesn’t go down there