Enteric nervous system
Jump to navigation
Jump to search
Clinic
- ENS or intrinsic nervous system is one of the main divisions of autonomic nervous system and consists of a mesh-like system of neurons that governs the function of the gastrointestinal tract.
- It is capable of acting independently of sympathetic and parasympathetic nervous systems, although it may be influenced by them
- ENS is capable of operating independently of the brain and spinal cord, but does rely on innervation from the vagus nerve and prevertebral ganglia in healthy subjects. However, studies have shown that the system is operable with a severed vagus nerve.
- ENS control the motor functions of the GI tract, in addition to the secretion of GI enzymes.
- These neurons communicate through many neurotransmitters similar to the CNS, including acetylcholine, dopamine, and serotonin
Types
Auerbach's plexus
- Also known as the myenteric plexus, is a collection of unmyelinated fibers and postganglionic autonomic cell bodies that lie between the circular and longitudinal layers of the muscularis externa in the GI tract.
- These neurons provide motor inputs to both layers of the muscularis externa and provide both parasympathetic and sympathetic input.
- The anatomy of the plexus is similar to the anatomy of CNS. The plexus includes sensory receptors, such as chemoreceptors and mechanoreceptors, that are used to provide sensory input to the interneurons in the enteric nervous system.
- The plexus is the parasympathetic nucleus of origin for the vagus nerve and communicates with the medulla oblongata through both the anterior and posterior vagal nerves.
Submucosal plexus
- Also known as Meissner's plexus is found in the submucosal layer of GI tract.
- It functions as a pathway for the innervation in the mucosa layer of GI wall.