The next tunic is the muscularis, which consists of an inner layer of circular smooth muscle and an outer layer of longitudinal smooth muscle. Two exceptions are the upper esophagus, where the muscles are striated, and the stomach, where there are three layers of smooth muscle. Another nerve plexus, the myenteric plexus, which consists of nerve fibers and parasympathetic cell bodies, is between these two muscle layers. Together, the submucosal and myenteric plexuses constitute the intramural (meaning, within the walls) plexus. The intramural plexus is extremely important in the control of movement and secretion.
