Anatomy & Physiology
A practical map of the body's structures and systems
Lesson 17 of 20
Digestive system
The digestive system breaks food into absorbable molecules and eliminates unabsorbed material. Digestion involves mechanical processing, chemical breakdown, movement, absorption, and secretion. The gastrointestinal tract works with accessory organs such as the liver, pancreas, and gallbladder. Nutrients enter circulation largely through the small intestine.
Key points
- Peristalsis moves contents along the gastrointestinal tract.
- The stomach mixes food and begins substantial protein digestion.
- The small intestine is the principal site of nutrient digestion and absorption.
- The liver processes absorbed substances and produces bile; the gallbladder stores and releases bile.
- The pancreas contributes digestive enzymes and bicarbonate to the small intestine.
- The large intestine absorbs water and helps form stool.
Key terms
- Peristalsis
- Coordinated muscular waves that propel contents through a hollow organ.
- Small intestine
- Digestive organ where most nutrient absorption takes place.
- Villus
- Small projection increasing absorptive surface in the small intestine.
- Bile
- Liver-produced fluid that aids fat digestion.
- Pancreas
- Organ contributing digestive secretions and endocrine hormones.
Memory tip
Food pathway: mouth, esophagus, stomach, small intestine, large intestine.
Clinical note
Avoid deep abdominal contact without appropriate training, consent, and consideration of the client's condition.
Unit checkpoint
Lock it in: match the terms, then test yourself.