Which term describes wave-like muscle movements that push food through the digestive system?

• A. Digestion
• B. Segmentation
• C. Peristalsis
• D. Absorption

Answer: (C)

Peristalsis describes the coordinated, wave-like contractions of the smooth muscle in the digestive tract that move contents forward. As a contraction travels, the circular muscle behind the bolus tightens to push it ahead, while the longitudinal muscle ahead shortens to help propel it along. This propulsive action, driven by the enteric nervous system and gut pacemaker cells, is the main way food is moved through the esophagus and intestines. In contrast, segmentation mixes and churns contents without net forward movement, digestion refers to chemical and mechanical breakdown, and absorption is the uptake of nutrients.