Myenteric Plexus

Myenteric Plexus

The myenteric plexus, also known as Auerbach’s plexus, together with Meissner’s plexus (submucosal plexus) forms the enteric nervous system which regulates the function of the gastrointestinal system.

The myenteric plexus is located between the inner and outer muscle layers of the muscularis externa. The submucosal plexus (Meissner’s plexus), on the other hand, is located in the submucosa.

This diagram illustrates the four layers of the gastrointestinal tract:

  • Mucosa – consists of 3 layers
    1. Epithelium
    2. Lamina Propria
    3. Muscularis Mucosae
  • Submucosa – connective tissue, submucosal plexus and blood vessels/lymphatics
  • Muscularis Externa – 3 muscle layers in the stomach, 2 in the small/large intestines surrounding the myenteric plexus:
    1. Circular (inner)
    2. Longitudinal (outer)
  • Adventitia/serosa – serous membrane which covers the muscularis externa

The myenteric plexus contains both parasympathetic and sympathetic fibres and supplies the circular and longitudinal muscle layers with motor innervation.

Hirschsprung’s disease is a congenital disorder of the newborn in which ganglion cells of the myenteric plexus are absent due to failure of the cells from the neural crest to migrate into the large intestine as a part of the normal formation of the enteric nervous system during fetal development. The disorder often presents with the baby failing to pass meconium (first stool) following delivery.

Learn more about the anatomy of the autonomic nervous system in this tutorial.