Digestive System Flashcards
Digestive System functions
- breakdown macromolecules to absorbable units
- rid body on non-digestible wastes
Lumen
tube of GI tract
Mucosa
- mucous secreting membrane
- lubricates, protects from self-digestion
Submucosa
- connective tissue
- blood vessels, lymph vessels, nerves
Muscularis
two layers of smooth muscle
Serosa
connective tissue that secretes a lubricating fluid
Amylase
enzyme that digests starch
Pharynx
passage way for food and air
Esophagus
muscular tube that conducts food from pharynx to stomach via peristalsis
Functions of Stomach
- storage of food
- mechanical and chemical digestion
How does the stomach prevent self-digestion?
- mucus is secreted which neutralizes acid
- without hydrochloric acid, pepsin is inactive (pepsinogen)
- high replacement rate of cells
heartburn
- valve that keeps stuff in stomach is weak
- stomach contents (acidic) move up esophagus
Ulcers
stomach lining eroded by gastric juices
Absorption in the small intestine is all about…
Surface area (circular folds, villi, microvilli)
How does the liver aid digestion?
It produces bile