Digestive System Study Guide Flashcards
Hard outer protective layer of the teeth
Enamel
Bone-like material that surrounds the pulp
Dentin
Houses the nerves and blood vessels of teeth
Pulp
Anchor the teeth to the jawbone
Periodontal membranes
Taste food; aids in the mechanical digestion of food; pushes bolus to pharynx
Tongue: Taste buds
Closes off nasopharynx when swallowing
Soft palate
Covers glottis during swallowing to prevent choking
Epiglottis
Space for the food bolus to travel through
Lumen
Nonkeratinized stratified squamous epithelium provides a protective lining
Mucosa
Contains blood vessels, lymphatic vessels, nerves, and glands; the glands secrete mucus into the lumen to aid in the transport of food
submucosa
Moves the food via peristalsis
Muscularis
(two layers of smooth muscle)
Relaxes to allow the bolus into the stomach and then contracts to close; prevents acid from entering the esophagus
Lower esophageal sphincter
Produces gastric juice composed of pepsinogen and hydrochloric acid (pH 2; kills bacteria and converts pepsinogen to pepsin); the semiliquid food is now called chyme
Mucosa
(gastric pits)
Mechanical digestion of food via peristalsis
Muscularis
(three layers of smooth muscle)
Controls the movement of chyme into the small intestine
Pyloric Sphincter
Produces brush border enzymes (e.g., maltase, sucrase, lactase, peptidases, and lipases) for chemical digestion of the chyme; absorbs nutrients; goblet cells produce mucus
Mucosa
(simple columnar epithelium forms folds called villi; cells contain microvilli)
Absorbs and transports chylomicrons (contains fat in the form of triglycerides)
Villus
Absorb and transport glucose and amino acids
Villus: Blood capillaries
Receives bile from liver and gallbladder and pancreatic juice from pancreas for chemical digestion of the chyme; absorbs nutrients
Duodenum
(the first part of the small intestine)
Produce bile that contains bile salts, bicarbonate ions (neutralizes the acidic chyme), and bilirubin (makes bile green)
Liver
Collects the bile produced by the hepatocytes
Bile canaliculi
Collects the bile from the bile canaliculi
bile duct
Brings oxygenated blood to the liver
Hepatic artery
Transports nutrient-rich blood from the GI tract to the liver
Hepatic portal vein