Nerves

Nerves

The stomach and duodenum possess both intrinsic and extrinsic nerve supplies. The intrinsic nerves exist principally in two plexuses, the myenteric plexus of Auerbach and the submucosal plexus of Meissner. Compared with the rest of the gut, the submucosal plexus of the stomach contains relatively few ganglionic cells, as does the myenteric plexus in the fundus. However, in the antrum the ganglia of the myenteric plexus are well developed. The extrinsic supply is derived mainly from the vagus nerves (cranial nerve X), fibres of which originate in the brainstem. The vagal plexus around the oesophagus condenses into bundles that pass through the oesophageal hiatus ( Figure 67.2 ), the posterior bundle being usually identifiable as a large nerve trunk. Vagal fibres are both a ff erent (sensory) and e ff erent. The e ff erent fibres are involved in the receptive relaxation of the stomach and the stimulation of gastric motility , as well as having the well-known secretory function. The sympathetic supply is derived mainly from the coeliac ganglia.