NETTER - Neuroscience Flash Cards

Enteric Nervous System
1. Vagus nerve
2. Splanchnic nerve
3. Celiac or superior mesenteric ganglion (collateral ganglion)
4. Mesenteric nerves
5. Myenteric plexus (Auerbach’s plexus)
6. Submucous (submucosal) plexus (Meissner’s plexus)
Comment: The enteric nervous system consists of approximately
100 million neurons arranged principally in the submucosal
(Auerbach’s) and myenteric (Auerbach’s) plexuses. Enteric neurons
and their plexuses regulate peristaltic responses (which may occur
without extrinsic control), pacemaker activity, and automated
secretory activity. Extrinsic (autonomic) input contacts only a small
number of these enteric neurons but may help to coordinate their
activity. If the intrinsic enteric neurons (neural crest origin) fail to
develop or migrate properly, a disorder called Hirschsprung’s disease
(chronic megacolon) occurs. The proper circuitry for peristalsis,
pacemaker activity, and secretomotor functions is not present, and
the autonomic extrinsic nerves cannot achieve effective coordination
of neural circuitry that is mainly absent. The lack of peristalsis and
smooth muscle tone results in megacolon, with hypertrophy and
distention.
Regional Neuroscience See book 9.61