Peristalsis

Definition

Peristalsis is a series of wave-like muscle contractions that move food through the digestive tract. It occurs in the esophagus, stomach, and intestines to facilitate digestion and absorption of nutrients.

5 Must Know Facts For Your Next Test

1. The process of peristalsis begins in the esophagus when a bolus of food is swallowed.
2. Peristaltic waves are smooth muscle contractions controlled by the autonomic nervous system.
3. In the small intestine, peristalsis mixes chyme with digestive enzymes and bile for nutrient absorption.
4. Peristalsis also helps move waste through the large intestine toward excretion.
5. Disorders such as achalasia can affect peristalsis, leading to difficulty swallowing or constipation.

Review Questions

• What type of muscle contraction is involved in peristalsis?
• How does peristalsis contribute to nutrient absorption in the small intestine?
• What role does peristalsis play in the large intestine?

Related terms

Bolus: A mass of chewed food ready to be swallowed.

Chyme:

The semi-fluid mass of partly digested food expelled by the stomach into the duodenum.

Autonomic Nervous System: The part of the nervous system responsible for controlling involuntary bodily functions, including peristalsis.