Small Intestine
Once processed and digested by the stomach, the milky chyme is squeezed through the pyloric sphincter into the small intestine. Once past the stomach a typical peristaltic wave will only last for a few seconds, travelling at only a few centimeters per second. Its primary purpose is to mix the chyme in the intestine rather than to move it forward in the intestine. Through this process of mixing and continued digestion and absorption of nutrients, the chyme gradually works its way through the small intestine to the large intestine.
In contrast to peristalsis, segmentation involves coordinated smooth muscle contractions that result in that churning and mixing without pushing materials further down the digestive tract.
During vomiting the propulsion of food up the esophagus and out the mouth comes from contraction of the abdominal muscles; peristalsis does not reverse in the esophagus.
Read more about this topic: Gut Motility
Famous quotes containing the words small and/or intestine:
“What strikes me as odd now is how much my father managed to get across to me without those heart-to-hearts which I’ve read about fathers and sons having in the study or in the rowboat or in the car.... Somehow I understood completely how he expected me to behave, in small matters as well as large, even though I can’t remember being given any lectures about it beyond the occasional, undramatic “You might as well be a mensch.””
—Calvin Trillin (20th century)
“Which came first the intestine or the tapeworm?”
—William Burroughs (b. 1914)