Digestion

Definition

Digestion is the process by which the body breaks down food into smaller components that can be absorbed and utilized for energy, growth, and cell repair. It involves both mechanical and chemical processes starting from the oral cavity through to the gastrointestinal tract.

5 Must Know Facts For Your Next Test

1. The digestion process starts in the mouth with mechanical breakdown by teeth and chemical breakdown by saliva.
2. Enzymes like amylase in saliva begin carbohydrate digestion in the oral cavity.
3. The stomach uses acid and enzymes like pepsin to further break down proteins into smaller peptides.
4. The small intestine is where most nutrient absorption occurs, facilitated by enzymes from the pancreas and bile from the liver.
5. Peristalsis is the muscular movement that pushes food through the digestive system.

Review Questions

• What role does saliva play in digestion?
• Where does most nutrient absorption occur within the digestive system?
• How do peristalsis movements aid in digestion?

Related terms

Enzyme: A protein that catalyzes chemical reactions, including those that break down food during digestion.

Peristalsis:

Wave-like muscle contractions that move food through the digestive tract.

Bile:

A fluid produced by the liver that aids in digesting fats.