The enteric nervous system

The enteric nervous system is the network of nerves that surrounds and governs the digestive system. Because it contains a great number of nerve cells, it is sometimes called the 'second brain'; there is a constant communication between the gut and the brain. This connection explains why emotional states are felt in the stomach and the gut. The enteric system is a concrete example of the relationship between body and emotion. Expressions like 'I had a gut feeling' point to this gut-brain relationship.