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The enteric nervous system is one of the main divisions of the autonomic nervous system (ANS).
It consists of a system of neurons that governs the function of the gastrointestinal tract.
It is capable of acting independently of the sympathetic and parasympathetic nervous systems.
The sympathetic and parasympathetic nervous systems may be influenced the enteric nervous system.
It is derived from neural crest cells, and is embedded in the lining of the gastrointestinal system.
The enteric nervous system consists of some 500 million neurons.
It has one two-hundredth of the number of neurons in the brain.
It has five times as many as the one hundred million neurons in the human spinal cord.
It begins in the esophagus and extending down to the anus.
The enteric nervous system is embedded in the lining of the gastrointestinal system, beginning in the esophagus and extending down to the anus.
The enteric nervous system can and does function autonomously, but normal digestive function requires communication links between this intrinsic system and the central nervous system.
Its neurons of the ENS are collected into two types of ganglia: myenteric (Auerbach’s) and submucosal (Meissner’s) plexuses.
Myenteric plexuses are located between the inner and outer layers of the muscularis externa.
The submucosal plexuses are located in the submucosa.
The ENS is capable of autonomous functions, but it receives considerable innervation from the autonomic nervous system.
It normally communicates with the central nervous system (CNS) through the parasympathetic nervous system via the vagus nerve and the sympathetic nervous system via the prevertebral ganglia.
The enteric nervous system includes efferent neurons, afferent neurons, and interneurons.
The enteric nervous system capable of carrying reflexes in the absence of CNS input.
The ENS contains sensory receptors, primary afferent neurons, interneurons, and motor neurons.
The sensory neurons of the enteric nervous system can report on mechanical and chemical conditions in the G.I. tract.
The motor neurons in the enteric nervous system control muscle peristalsis and churning of intestinal contents.
The ENS contains sensory receptors, primary afferent neurons, interneurons, and motor neurons.
Other neurons of the enteric nervous system control the secretion of enzymes.
The ENS operates independently of the brain and the spinal cord.
These links take the form of parasympathetic and sympathetic fibers that connect either the central and enteric nervous systems or connect the central nervous system directly with the digestive tract.
Through these cross connections, the gut can provide sensory information to the CNS, and the CNS can affect gastrointestinal function.
Connection to the central nervous system also means that signals from outside of the digestive system can be relayed to the digestive system: for instance, the sight of appealing food stimulates secretion in the stomach.
It has efferent neurons, afferent neurons, and interneurons which allow the ENS to carry reflexes and act as an integrating center in the absence of CNS input.
Sensory neurons assess mechanical and chemical conditions.
The motor neurons control peristalsis and churning of intestinal contents through intestinal muscles.
Enteric neurons control the secretion of enzymes, and the enteric nervous system also makes use of more than 30 neurotransmitters, most of which are identical to the ones found in CNS, such as acetylcholine, dopamine, and serotonin.
More than 90% of the body’s serotonin and 50% of the body’s dopamine lies in the gut.
The enteric nervous system can alter its response depending on such factors as the quantity and nutrient composition of food.
In addition, ENS contains support cells similar to the blood–brain barrier of cerebral blood vessels.