Which process moves food through the digestive tract by rhythmic muscular contractions?

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

Answer: (B)

The process is peristalsis, which refers to the coordinated, rhythmic contractions of smooth muscle in the walls of the digestive tract that push contents forward. These waves of contraction occur in a sequence: a ring of muscle behind the food constricts to narrow the lumen, while the muscle ahead relaxes, creating a forward propulsive motion. This muscular choreography moves the swallowed food all the way from the esophagus through the intestines.

This is different from digestion, which is about breaking food down chemically; absorption, which is about nutrients entering the bloodstream; and filtration, which isn’t a typical digestive process. Peristalsis is specifically about propulsion, explaining why it best fits the description of moving food through the digestive tract via rhythmic contractions.