Glossary · Y học
Vagus nerve
The main component of the parasympathetic nervous system, overseeing many essential bodily functions including mood, immune response, digestion and heart rate. It is one of the connections between the brain and the gastrointestinal tract, sending information about the state of the inner organs to the brain via afferent fibres.
According to the review by Breit et al. (2018), the vagus nerve is the main component of the parasympathetic nervous system, overseeing a vast array of crucial functions including control of mood, immune response, digestion and heart rate.
It establishes one of the connections between the brain and the gastrointestinal tract, and sends information about the state of the inner organs to the brain via afferent fibres (sensory fibres running from the organs to the central nervous system). The abdominal vagal afferents include mechanoreceptors, chemoreceptors and tension receptors in the oesophagus, stomach and proximal small intestine; their sensory cell bodies lie in the nodose ganglia and send information to the nucleus tractus solitarii (NTS) in the brainstem.
Breit et al. report that stimulating vagal afferent fibres in the gut influences monoaminergic systems in the brainstem — systems that play important roles in psychiatric conditions such as mood and anxiety disorders. The same review notes PRELIMINARY evidence that gut bacteria may benefit mood and anxiety, partly by affecting the activity of the vagus nerve.