Esophagus Model Of Contraction

Hoehn). An antagonist is a muscle that reverses, or opposes, the action of another muscle. A synergist is a muscle that aids the action of a prime mover by effecting the same movement or by stabilizing joints across which the prime which the prime mover acts, preventing undesirable movements. The sliding filament model of contraction states that during contraction the thin filaments slide past the “thick ones so that the actin and myosin filaments overlap to a greater degree” (Marieb & Hoehn). When the nervous system stimulates muscle fibers, the myosin heads on the thick filaments latch onto myosin-binding sites on actin in the thin filaments, and the sliding begins. These cross bridge attachments form and break several times during a contraction, tension and propel the thin filaments toward the

The bolus then goes to the pharynx where swallowing occurs. During deglutition in the pharynx there is a “flexible flap of elastic cartilage that’s function is to keep food out of the lower respiratory passages” called the epiglottis (Human). The bolus then goes to through the esophagus where segmentation(circular muscle contractions of esophagus that allows the bolus to mix) and peristalsis(longitudinal muscle contractions of the esophagus that allows the bolus to be push down bolus to the stomach) happens. Then it goes through “ringlike muscles that contract/close a bodily passage or opening” called sphincters (Sphincter). The bolus goes through one called the gastroesophageal between the end of the esophagus and the beginning of the stomach in order to enter the stomach. In the stomach, the bolus is then turned into chyme which is “partially digested food by the secretion of HCl and Pepsin” (Human). After the stomach, the chyme goes “through the pyloric sphincter to enter the initial part of the small intestine, the duodenum” (Sphincter). Chyme is mixed with bile from the