| A | B |
|---|
| absorption | uptake of small nutrient molecules by an organism’s own body |
| acid chyme | mixture of recently swallowed food and gastric juice |
| alimentary canal | digestive tract consisting of a tube running between a mouth and an anus |
| appendix | fingerlike extension of the vertebrate cecum contains a mass of white blood cells that contribute to immunity |
| bile | produced in the liver stored in the gallbladder and acts as a detergent to aid in the digestion and absorption of fats |
| bolus | lubricated ball of chewed food |
| bulk-feeder | eats relatively large pieces of food |
| carnivore | eats other animals |
| cecum | blind outpocket of a hollow organ such as an intestine |
| chylomicron | small intracellular globules composed of fats that are mixed with cholesterol and coated with special proteins |
| complete digestive tract | digestive tube that runs between a mouth and an anus |
| digestion | process of breaking down food into molecules small enough for the body to absorb |
| duodenum | first section of the small intestine where acid chyme from the stomach mixes with digestive juices |
| elimination | passing of undigested material out of the digestive compartment |
| enzymatic hydrolysis | splits macromolecules from food by the enzymatic addition of water |
| epiglottis | flap that blocks the top of the windpipe prevents the entry of food or fluid into the respiratory system |
| esophagus | channel that conducts food from the pharynx to the stomach |
| essential amino acid | cannot synthesize itself and must obtain from food |
| essential fatty acids | unsaturated fatty acids that animals cannot make |
| essential nutrient | organism must absorb in preassembled form because it cannot be synthesized |
| extracellular digestion | breakdown of food outside cells |
| feces | wastes of the digestive tract |
| fluid-feeder | lives by sucking nutrient-rich fluids from another living organism |
| gallbladder | stores bile and releases it as needed into the small intestine |
| gastrovascular cavity | serves as the site of extracellular digestion and a passageway to disperse materials throughout most of an animal’s body |
| hepatic portal vessel | conveys nutrient-laden blood from the small intestine to the liver |
| herbivore | animal that eats plants |
| ingestion | heterotrophic mode of nutrition in which other organisms or detritus are eaten whole or in pieces |
| intracellular digestion | chemical digestion to occur within the cytoplasm of a cell |
| lacteal | lymph vessel extending into the core of an intestinal villus and serving as the destination for absorbed chylomicrons |
| large intestine colon | functions mainly in water absorption and the formation of feces |
| liver | poisonous chemicals in the blood |
| malnourished | missing one or more essential nutrients |
| microvillus | fingerlike projections of the epithelial cells in the lumen of the small intestine that increase its surface area |
| mineral | element other than hydrogen oxygen or nitrogen that an organism requires for proper body functioning |
| omnivore | consumes both meat and plant material |
| oral cavity | mouth of an animal |
| overnourishment | diet that is chronically excessive in calories |
| pancreas | secretes digestive enzymes into the small intestine via a duct and the hormones insulin and glucagon into the blood |
| pepsin | enzyme present in gastric juice that begins the hydrolysis of proteins |
| pepsinogen | inactive form of pepsin that is first secreted by specialized (chief) cells located in gastric pits of the stomach |
| peristalsis | Rhythmic waves of contraction of smooth muscle that push food along the digestive tract |
| pharynx | area in the vertebrate throat where air and food passages cross |
| pyloric sphincter | muscular ring that regulates the passage of food out of the stomach and into the small intestine |
| rectum | terminal portion of the large intestine where the feces are stored until they are eliminated |
| ruminant | animal with an elaborate multicompartmentalized stomach specialized for an herbivorous diet |
| salivary amylase | enzyme that hydrolyzes starch |
| salivary glands | substances to lubricate food adhere together chewed pieces into a bolus and begin the process of chemical digestion |
| small intestine | principal site of the enzymatic hydrolysis of food macromolecules and the absorption of nutrients |
| sphincter | ringlike valve consisting of modified muscles in a muscular tube |
| stomach | food and performs preliminary steps of digestion |
| substrate-feeder | organism that lives in or on its food source eating its way through the food |
| suspension-feeder | sifts small food particles from the water |
| undernourishment | diet that is chronically deficient in calories |
| villus | finger-like projection of the inner surface of the small intestine |
| vitamin | organic molecule required in the diet in very small amounts |
