Question

Describe the myenteric plexus below. When it becomes activated what is the major physiological response? When would this plexus be activated?

Answer 1

Myenteric plexus also known as Aurbech's plexus is one of important plexus supplying the oesophagus, stomach and intestine. It is the part of enteric nervous system. It innervates the circular and longitudinal muscles and contain sympathetic and parasympathetic innervations.
It is present in the muscularis propria layer of GIT between longitudinal and circular smooth muscle layer. Presence of food in GIT is sensed by mechanoreceptors present in GIT. This stimulates the autonomic nervous system. Stimulation of sympathetic nervous system results in decreased peristalsis movement of GIT and slows process of digestion. Parasympathetic stimulation results in increased contraction of GIT and stimulates digestive juices secretion which aids in digestion.
The plexus stimulates in the presence of food in GIT to increase digestion. In absence of food the plexus is not stimulated resulting in relaxation of GIT.
The meyenteric plexus helps regulate the GIT motility and peristalsis movement through sympathetic and parasympathetic innervations.