What is Peristalsis
Peristalsis is a condition in which the muscles radically contract symmetrically and relaxes which leads to a wave within the muscular tube. When this process begins in human beings it causes the contractions of the smooth muscles that line the digestive tract. This term has been derived from the same mechanism that is often used by earthworms to drive their bodies along due to the wrapping around that is often characteristic of the process. The earthworms initiate a muscularly process that once begun propels them forward thus enabling them to move along. In ordinary life the smooth muscles contract in order to force food down the esophagus and the gastrointestinal tract in to the stomach. This movement is initiated by the smooth muscle from the mouth once the food has been sufficiently chewed in order to prevent the food from moving back in to the mouth. The smooth muscles ensure that the food is gradually moved forward in longitudal movements till it reaches the stomach.
Once the food has been chewed sufficiently it’s swallowed and goes down the esophagus as a bolus. The movement is designed in such a way that the food is pushed down and hence cannot return to the mouth. This muscles force the food bolus to move in such a way that it will move from the mouth in to the stomach with no possibility of reversing the movement. The primary peristaltic wave begins when the food bolus gets in to the esophagus during swallowing; the wave lasts about 8 o nine seconds and will continue even if the food gets stuck at some point in the process. Mostly food gets stuck when the esophagus is not well lubricated or if the bolus moves slower than the main peristaltic wave. In such an event the secondary wave and the receptor stretch which lines the esophagus initiates a local reflex response which will force the food down the esophagus and this will continue till the food is in the stomach.
When the food has been processed in the stomach it’s then squeezed in to the small intestines. The peristaltic wave will continue even in the intestine only this time the purpose will be to mix the food rather than move it forward. This process of churning up the food enables the digestion and absorption of the nutrients as the doo gradually makes its way in to the larger intestines.
Vomiting is caused by propulsion of the food from the esophagus as the peristaltic wave does not reverse in the esophagus. Once the processed mix is in the large intestines its periodically moved in mass movements which occurs about three times in a day which force the now fecal stuff from the large intestine to the colon and onward to the rectum. This will continue until the muscles will be stretched to the limit in which case the person will feel an urge to empty their bowels thus completing the process that begun from the mouth and ends up once the fecal matter is passed out of the body.