North Seattle College EMT Entrance Practice Exam 2025 - Free EMT Practice Questions and Study Guide

The term for the involuntary wave-like contraction of smooth muscles in the digestive tract is peristalsis. Peristalsis is a crucial physiological process that helps in moving food through the gastrointestinal tract. It involves coordinated contractions and relaxations of the smooth muscle layers surrounding the digestive organs, effectively pushing the contents along the tract.

This process begins in the esophagus when a bolus of food is swallowed, and it continues throughout the stomach and intestines, ensuring that food is mixed with digestive juices and propelled towards the rectum for elimination. Understanding peristalsis is vital for comprehending how the body digests food and absorbs nutrients effectively.

The other terms listed are related to the digestive process but refer to different functions. Segmentation, for instance, refers to the rhythmic contraction of the circular muscles in the intestines, which helps to mix and break down food rather than move it along the tract as peristalsis does. Digestion is the broader process of breaking down food into smaller components that can be absorbed, while absorption specifically concerns the uptake of nutrients from the digestive tract into the bloodstream.