Which term describes the wave-like contractions that move food through the digestive tract?

• A. Peptic ulcer
• B. Uvula
• C. Gingivitis
• D. Peristalsis

Answer: (D)

Peristalsis is the coordinated, rhythmic contraction and relaxation of the smooth muscles in the digestive tract that propels the contents forward. Behind the swallowed mass, the circular muscles contract to squeeze it onward, while the longitudinal muscles ahead relax, creating a traveling wave that pushes food through the esophagus, stomach, and intestines. This propulsion is driven by the enteric nervous system and autonomic inputs, ensuring a forward movement and appropriate transit time. It’s different from segmentation, which mainly stirs and mixes contents rather than pushing them along. The other terms don’t describe this movement: a peptic ulcer is a lesion from acid damage, the uvula is a soft-tissue structure at the back of the throat, and gingivitis is inflammation of the gums.