Sections
Key Terms
Key Terms
- alimentary canal
- tubular digestive system with a mouth and anus
- aminopeptidase
- protease that breaks down peptides to single amino acids; secreted by the brush border of small intestine
- anus
- exit point for waste material
- bile
- digestive juice produced by the liver; important for digestion of lipids
- bolus
- mass of food resulting from chewing action and wetting by saliva
- carboxypeptidase
- protease that breaks down peptides to single amino acids; secreted by the brush border of the small intestine
- carnivore
- animal that consumes animal flesh
- cephalic phase
- first phase of digestion, controlled by the neural response to the stimulus provided by food
- cholecystokinin
- hormone that stimulates the contraction of the gallbladder to release bile
- chylomicron
- small lipid globule
- chyme
- mixture of partially digested food and stomach juices
- chymotrypsin
- pancreatic protease
- digestion
- mechanical and chemical break down of food into small organic fragments
- dipeptidase
- protease that breaks down peptides to single amino acids; secreted by the brush border of small intestine
- duodenum
- first part of the small intestine where a large part of digestion of carbohydrates and fats occurs
- elastase
- pancreatic protease
- endocrine system
- system that controls the response of the various glands in the body and the release of hormones at the appropriate times
- esophagus
- tubular organ that connects the mouth to the stomach
- essential nutrient
- nutrient that cannot be synthesized by the body; it must be obtained from food
- gallbladder
- organ that stores and concentrates bile
- gastric inhibitory peptide
- hormone secreted by the small intestine in the presence of fatty acids and sugars; it also inhibits acid production and peristalsis in order to slow down the rate at which food enters the small intestine
- gastric phase
- digestive phase beginning once food enters the stomach; gastric acids and enzymes process the ingested materials
- gastrin
- hormone which stimulates hydrochloric acid secretion in the stomach
- gastrovascular cavity
- digestive system consisting of a single opening
- gizzard
- muscular organ that grinds food
- herbivore
- animal that consumes strictly plant diet
- ileum
- last part of the small intestine; connects the small intestine to the large intestine; important for absorption of B-12
- ingestion
- act of taking in food
- intestinal phase
- third digestive phase; begins when chyme enters the small intestine triggering digestive secretions and controlling the rate of gastric emptying
- jejunum
- second part of the small intestine
- lactase
- enzyme that breaks down lactose into glucose and galactose
- large intestine
- digestive system organ that reabsorbs water from undigested material and processes waste matter
- lipase
- enzyme that chemically breaks down lipids
- liver
- organ that produces bile for digestion and processes vitamins and lipids
- maltase
- enzyme that breaks down maltose into glucose
- mineral
- inorganic, elemental molecule that carries out important roles in the body
- monogastric
- digestive system that consists of a single-chambered stomach
- omnivore
- animal that consumes both plants and animals
- pancreas
- gland that secretes digestive juices
- pepsin
- enzyme found in the stomach whose main role is protein digestion
- pepsinogen
- inactive form of pepsin
- peristalsis
- wave-like movements of muscle tissue
- proventriculus
- glandular part of a bird’s stomach
- rectum
- area of the body where feces is stored until elimination
- roughage
- component of food that is low in energy and high in fiber
- ruminant
- animal with a stomach divided into four compartments
- salivary amylase
- enzyme found in saliva, which converts carbohydrates to maltose
- secretin
- hormone which stimulates sodium bicarbonate secretion in the small intestine
- small intestine
- organ where digestion of protein, fats, and carbohydrates is completed
- somatostatin
- hormone released to stop acid secretion when the stomach is empty
- sphincter
- band of muscle that controls movement of materials throughout the digestive tract
- stomach
- saclike organ containing acidic digestive juices
- sucrase
- enzyme that breaks down sucrose into glucose and fructose
- trypsin
- pancreatic protease that breaks down protein
- villi
- folds on the inner surface of the small intestine whose role is to increase absorption area
- vitamin
- organic substance necessary in small amounts to sustain life