Gastrointestinal tract is innervated with intrinsic innervation of Auerbach's and Meissner's plexus of nerves. Their arrangement is as follows (AIIMS May 2014)
|A||Former as sub-serosal plexus and latter as myenteric plexus|
|B||Former as myenteric plexus and latter as mucosal plexus|
|C||Former as sub-mucosal plexus and latter as serosal plexus|
|D||Former as myenteric plexus and latter as sub-mucosal plexus|
Former as myenteric plexus and latter as sub-mucosal plexus
1. Part of the enteric nervous system, Auerbach's plexus (or myenteric plexus) exists between the longitudinal and circular layers of muscularis externa in the gastrointestinal tract and provides motor innervation to both layers and secretomotor innervation to the mucosa.
2. It arises from cells in the dorsal nucleus of vagus, the parasympathetic nucleus of origin for the tenth cranial nerve (Vagus), located in the medulla oblongata. The fibers are carried by both the anterior and posterior vagal nerves.
3. The nerves of the small intestines are derived from the plexuses of parasympathetic nerves around the superior mesenteric artery.
4. From this source they run to the myenteric plexus (Auerbach's plexus) of nerves and ganglia situated between the circular and longitudinal muscular fibers from which the nervous branches are distributed to the muscular coats of the intestine.
5. From this a secondary plexus, the plexus of the submucosa (Meissner's plexus, submucous plexus) is derived, and is formed by branches which have perforated the circular muscular fibers.
6. This plexus lies in the submucous coat of the intestine; it also contains ganglia from which nerve fibers pass to the muscularis mucosae and to the mucous membrane.
7. The nerve bundles of the submucous plexus are finer than those of the myenteric plexus.