Which process moves food through the digestive tract by wave-like contractions?

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

Answer: (B)

Peristalsis is the wave-like muscular contraction that moves food through the digestive tract. The smooth muscle layers in the gut—circular and longitudinal—contract in a coordinated sequence, creating rippling motions that propel the bolus forward from the esophagus through the intestines. This propulsion is guided by the enteric nervous system and local hormones, ensuring content moves along rather than just mixing.

Absorption refers to taking nutrients across the intestinal lining into the bloodstream, not to propulsion. Digestion is the breakdown of food into smaller molecules, which occurs before absorption. Segmentation involves alternating contractions that mix and churn contents to enhance digestion and contact with absorptive surfaces, rather than primarily pushing material forward.