The task of the stomach nerves
During digestion the stomach has some extremely important functions: It not only intakes the chewed food from the oesophagus but also mixes it with gastric juice it self-produces and passes the prepared chyme in a controlled manner to the intestine. The gastric nerves are there to ensure that these perfectly coordinated tasks run as smoothly as possible. They run through the entire stomach and keep the processes in balance.
The gastric nerves do not act completely independently: they are a part of the so-called enteric nervous system which controls all processes in the gastrointestinal tract and pervades our entire digestive system with control centres.
The enteric nervous system comprises approximately as many nerve cells as the human spinal cord. This fact, along with its ability to process stimuli independently and issue specific commands independently of our brains has given it a second name: the gut-brain. But our psyche can have an influence on the gastrointestinal tract- for example the excitement before an upcoming test can trigger a rumbling in the stomach, or our annoyance with our partner can spoil our appetite and ruin the romantic dinner we had planned.
The enteric nervous system is also influenced by the autonomic nervous system (ANS) which pervades the whole body:
- The sympathetic part (SNS) reduces the secretion of gastric juice and inhibits the movements of the stomach.
- The parasympathetic part (PSNS) stimulates blood circulation and gastric juice secretion and activates gastric motility.
Depending on the situation the influence of one area predominates. For example in a stress situation the functions of the stomach may be imbalanced.