Peristalsis is best described as what?

• A. Voluntary control of swallowing
• B. Rhythmic, involuntary, wavelike movement that helps move contents through the gastrointestinal tract
• C. Active transport across membranes
• D. Bodily movement of the skeleton

Answer: (B)

Peristalsis is the rhythmic, involuntary, wavelike contraction of the smooth muscle lining the gastrointestinal tract that propels swallowed material along the tract. This automatic motion is coordinated by the enteric nervous system and occurs without conscious control, which is why it’s described as involuntary. It’s different from active transport across membranes, a cellular process of moving substances through cell membranes, and from bodily movement of the skeleton, which involves voluntary use of skeletal muscles. Swallowing may be initiated voluntarily, but the peristaltic movement that pushes contents through the esophagus and intestines continues automatically.