![]() Peristalsis and segmenting movements are usually affected equally and in the same manner. Eructation of ruminal gases is an additional crucial function of motility in ruminants.Ībnormal motor function can take the form of increased or decreased motility. Prehension, mastication, and swallowing are the other functions of alimentary tract motility that are essential for normal function. In ruminants these movements are of major importance in the forestomach. The most important functions of alimentary tract motility are the peristaltic movements that move ingesta from the esophagus to the rectum, the segmentation movements that churn and mix the ingesta, and the tone of the sphincters. Disruption in gastrointestinal tract motility can result in the following: However, unlike the small intestine, the patterns of spikes vary greatly with the species and the area of the large intestine.Ībnormalities of stomach and intestinal motility represent the most common consequence of gastrointestinal tract disease. Normal cecal and colonic myoelectric activities, like those of the small intestine, are characterized by slow waves and spikes. It is replaced by the fed pattern, characterized by intermittent spike activity resembling the irregular phase. In nonruminants, and pigs and horses fed periodically, feeding abolishes the migrating myoelectric complex for several hours. The activity front is accompanied by intense muscular contraction that obliterates the lumen, preventing backflow of content as it propagates, or migrates, down the intestine. During the irregular phase, contractions mix the intestinal contents and propel them in an aboral direction. There is very little muscle contraction or transit of gut contents during the quiescent phase. 1 There are three phases of the migrating myoelectric complex:Īctivity front, characterized by intense, continuous spike activity The spiking activity, also known as the migrating myoelectric complex, is the myoelectric pattern in the stomach and small intestine of fasted nonruminants, fed and fasted ruminants, and pigs and horses fed ad libitum. Almost all spike activity in the intestine is superimposed on slow waves, which are important in controlling frequency and velocity at which spiking events occur. When an additional stimulus causes the membrane potential to exceed the excitation threshold, a spike or electrical response activity occurs, which is usually accompanied by contraction. Slow waves are constantly propagated from the stomach to the rectum. In the small intestine, the fundamental unit of electrical activity is the slow wave, which is a subthreshold fluctuation in membrane potential. The motility patterns in both the small and large intestine are similar among the species. The form and function of the small intestine of farm animals are similar between species, but the stomachs and large intestines vary considerably.
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