Enteric Nervous System
The enteric nervous system is the network of neurons in your gut that controls digestion, movement, and secretion. In Intro to Brain and Behavior, it shows how the nervous system extends beyond the brain and spinal cord.
What is the Enteric Nervous System?
The enteric nervous system, or ENS, is the neuron network built into the walls of the digestive tract. In Intro to Brain and Behavior, it is the part of the nervous system that shows the gut is not just a passive tube, it has its own control system for moving food, mixing it, and coordinating secretions.
A useful way to picture it is as a local control center. The ENS can make many routine digestive decisions on its own, like when to push food forward through peristalsis or when to adjust enzyme release. That is why it is often called the body’s “second brain,” although it does not think, plan, or reason the way the brain does.
The ENS has two major plexuses. The myenteric plexus mainly regulates motility, which means the muscle contractions that move material through the gut. The submucosal plexus focuses more on secretion and local blood flow, helping the intestines absorb nutrients and keep the tissue supplied with oxygen.
The system contains a very large number of neurons, which is one reason it can coordinate so much on its own. It also uses neurotransmitters and sensory information from the gut wall to respond to stretch, chemical changes, and the presence of food. So if the stomach stretches after a meal, ENS circuits can detect that and adjust movement and secretion without waiting for a command from the brain.
That does not mean the ENS is isolated. It constantly communicates with the central nervous system, especially through the vagus nerve and other pathways of the autonomic nervous system. The brain can influence digestion, and the gut can send signals back up, which is part of the gut-brain axis.
Because the ENS is built into the digestive tract, problems in its signaling can show up as changes in motility, pain, bloating, or irregular bowel function. That is why Intro to Brain and Behavior often connects the ENS to gastrointestinal disorders and to the way body state can shape mood, stress, and discomfort.
Why the Enteric Nervous System matters in Intro to Brain and Behavior
The enteric nervous system matters because it expands your idea of what the nervous system does. In Intro to Brain and Behavior, the course is not just about the brain as a thinking organ, but about how neural circuits regulate everyday body functions like digestion, hunger, and internal balance.
This term also helps you separate local control from brain control. Some digestive actions are handled right in the gut, while others are influenced by the brain through autonomic pathways. That distinction shows up when you explain why a meal, stress, or illness can change gut activity without changing conscious decisions.
It also gives you a clean way to connect biological systems to behavior and emotion. Students often meet the ENS when discussing the gut-brain axis, stress responses, or symptoms that appear in disorders like IBS. If you can trace how the gut sends signals, how the ENS processes them, and how the brain responds, you can explain both physiology and lived experience more clearly.
In other words, the ENS is a bridge concept. It sits right between nervous system anatomy, autonomic control, and the biological basis of mental and physical well-being.
Keep studying Intro to Brain and Behavior Unit 1
Official unit cheatsheet
open one-pagerHow the Enteric Nervous System connects across the course
Autonomic Nervous System
The ENS is closely tied to the autonomic nervous system because both regulate involuntary body functions. The autonomic nervous system can influence digestion from above, but the ENS does much of the local work inside the gut wall. Comparing the two helps you see which signals come from broader brain-body control and which happen through local enteric circuits.
Vagus Nerve
The vagus nerve is one of the main routes linking the brain and the gut. It carries information that can affect ENS activity and also helps send feedback from the digestive system back to the brain. When you study the vagus nerve with the ENS, you get the communication pathway that makes the gut-brain connection concrete.
Gut-Brain Axis
The ENS is a core part of the gut-brain axis, which describes the two-way communication between digestive processes and the central nervous system. If the gut is irritated, stressed, or inflamed, that information can shape brain responses, and brain state can shift digestion too. This connection shows up a lot in discussions of stress, mood, and gastrointestinal symptoms.
parasympathetic division
The parasympathetic division usually supports rest-and-digest activity, so it often lines up with digestive function. The ENS can keep working on its own, but parasympathetic input can amplify or fine-tune that activity. Pairing these terms helps you sort out the brain’s calming influence from the gut’s own local control.
Is the Enteric Nervous System on the Intro to Brain and Behavior exam?
A quiz question might ask you to identify which nervous system division controls gut motility, or to explain why digestion can continue even when brain input is reduced. In an essay or short-answer response, you may need to trace how the ENS responds to a meal, then explain how signals travel through the vagus nerve or autonomic pathways. You could also be asked to compare the myenteric and submucosal plexuses, or connect ENS dysfunction to symptoms like cramping, constipation, or irregular bowel activity. If a case study mentions stress and stomach upset, the ENS is part of the mechanism you should mention.
The Enteric Nervous System vs Autonomic Nervous System
These are related, but not the same. The autonomic nervous system is a broader control system that regulates involuntary functions throughout the body, while the enteric nervous system is the specialized neural network inside the digestive tract. The ENS can act on its own, but it also receives input from the autonomic nervous system.
Key things to remember about the Enteric Nervous System
The enteric nervous system is the gut’s own neural network, and it controls digestion from inside the digestive tract.
It can run many digestive processes on its own, including motility, secretion, and local blood flow.
The myenteric plexus mainly handles gut movement, while the submucosal plexus mainly handles secretion and circulation.
The ENS still communicates with the brain, especially through the vagus nerve and other autonomic pathways.
In Brain and Behavior, the ENS is a good example of how body systems and mental states connect through the gut-brain axis.
Frequently asked questions about the Enteric Nervous System
What is the enteric nervous system in Intro to Brain and Behavior?
It is the network of neurons in the digestive tract that controls many aspects of digestion. In this course, it shows that the nervous system includes more than the brain and spinal cord, since the gut has its own local control circuits.
Is the enteric nervous system part of the autonomic nervous system?
It is closely connected to the autonomic nervous system, but it is usually treated as its own division because it can operate independently in the gut. The autonomic nervous system influences digestion from the brain and spinal cord side, while the ENS handles local digestive control.
How does the enteric nervous system communicate with the brain?
It communicates through neural pathways, especially the vagus nerve, and through chemical signaling between gut and brain. That two-way communication is part of the gut-brain axis, which is why stress and digestion can affect each other.
What does the enteric nervous system control?
It controls gut motility, secretion, and local blood flow in the intestines. Those functions help move food, release digestive chemicals, and keep the intestinal tissue working properly.