What is the name of the muscular contractions that move food through the esophagus?

The correct answer is peristalsis, which refers to the coordinated, wave-like muscular contractions that occur in the smooth muscles of the digestive tract, particularly in the esophagus. This process is essential for propelling food from the mouth to the stomach. Peristalsis consists of two main actions: sequential contraction and relaxation of the muscle fibers that surround the esophagus. As these muscles contract behind the food bolus, they push it downward. This rhythmic, involuntary movement ensures that food is efficiently moved along the digestive tract.

Segmentation, on the other hand, involves the contraction of the muscles in a way that mixes and kneads the food, primarily occurring in the intestines to facilitate nutrient absorption rather than moving food along the digestive tract. Swallowing is the initial voluntary action of moving food from the mouth into the esophagus but does not describe the ongoing process of transporting food through the esophagus itself. Absorption refers to the process where nutrients from digested food are taken up into the bloodstream, which also occurs primarily in the intestines, not in the esophagus. Thus, peristalsis is the specific term that captures the essential function of moving food through the esophagus.