The esophagusThe esophagus is a straight, collapsible tube about 25cm long. It provides a passage way for food, and its muscular wall propels food from the pharynx to the stomach. The esophagus descends through the thorax to the posterior of the trachea. To allow the food to go down peristalsis has to occur. Peristalsis is a propelling movement including a wavelike movement.
Just above the point where the esophagus an the stomach join, some of the circular muscle fibers have increased sympathetic muscle tone. That forms the esophageal sphincter, or cardioesphageal sphincter. |