What is peristalsis?

What is peristalsis?

• A. The involuntary waves that move food through the digestive system
• B. The voluntary chewing actions that break down food
• C. The chemical digestion of proteins
• D. The absorption of nutrients into the blood

Answer: (A)

Peristalsis is the involuntary, wave-like contraction of the smooth muscle in the walls of the digestive tract that pushes food along the gut. As a wave passes, circular muscles ahead of the bolus contract while the longitudinal muscles behind it relax, then the pattern repeats to move the contents forward from the esophagus through the stomach and intestines. This process is controlled by the enteric nervous system and autonomic signals, so it happens without conscious effort. It’s different from voluntary chewing, enzymatic digestion, or nutrient absorption, which are separate steps in digestion.

Peristalsis is the involuntary, wave-like contraction of the smooth muscle in the walls of the digestive tract that pushes food along the gut. As a wave passes, circular muscles ahead of the bolus contract while the longitudinal muscles behind it relax, then the pattern repeats to move the contents forward from the esophagus through the stomach and intestines. This process is controlled by the enteric nervous system and autonomic signals, so it happens without conscious effort. It’s different from voluntary chewing, enzymatic digestion, or nutrient absorption, which are separate steps in digestion.