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Related to enterokinesia: enterokinase


the wormlike movement by which the alimentary canal or other tubular organs with both longitudinal and circular muscle fibers propel their contents, consisting of a wave of contraction passing along the tube. adj., adj peristal´tic.

When food is swallowed, it passes into the esophagus. Muscular contractions in the wall of the esophagus work the food downward, pushing it into the stomach. Here peristaltic contractions not only move the food in small amounts into the intestine but also aid in the disintegration of the food and help mix it with gastric juice. Peristalsis forces the food into and through the intestine for further digestion until the food waste finally reaches the rectum, from which it is periodically discharged from the body. The waves of peristalsis are irregular; they are stronger at some times than at others. They are also weaker in some people, notably the elderly.

Although the normal peristaltic wave is downward, it is sometimes reversed. Reverse peristaltic action may be triggered by mild digestive upsets or more serious disorders, such as an obstruction in the stomach or intestines.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.