Guide 06 / six systems
Digestive system
A long, intelligent processing line that turns food into the molecules the rest of the body can use.
The job
Breaks down food, absorbs nutrients and water, and packages the material the body cannot use.
Orient yourself
The digestive tract is a continuous tube with specialized regions. Accessory organs such as the liver, gallbladder, and pancreas add secretions that make chemical digestion and absorption possible.
Trace a pathway
Trace a meal from mouth to pharynx, esophagus, stomach, small intestine, and colon. Most nutrient absorption happens in the small intestine, while the colon concentrates what remains by reclaiming water.
Make the connection
- The liver processes absorbed nutrients before they enter the wider circulation.
- Smooth muscle moves contents through the tract with coordinated waves called peristalsis.
- The nervous and endocrine systems regulate secretion, appetite, and the timing of digestion.
Close the page
Can you explain it without looking?
Active recall turns recognition into understanding. Answer these prompts in your own words, then return to the guide only for the part you could not reconstruct.
Where does most nutrient absorption occur?
What is the difference between the digestive tract and an accessory organ?
Why is the colon important even though most digestion is already complete?