What type of muscle movement is described as peristalsis?

Peristalsis refers to the involuntary muscle contractions that occur in the walls of hollow organs, particularly in the digestive system. This process is crucial for moving food through the digestive tract, from the esophagus down to the intestines. During peristalsis, smooth muscles contract and relax in a coordinated manner to propel contents forward.

Involuntary muscle contractions, as seen in peristalsis, are automatic and are not under conscious control, distinguishing them from voluntary movements that require conscious effort. This is why the answer accurately reflects the nature of peristalsis. Understanding this concept is essential for those studying human physiology and the functioning of the digestive system.