What is a "vagus nerve"?

A vagus nerve is a singular, countable body part that extends from the brainstem to various organs in the body. It is an essential component of the autonomic nervous system, responsible for regulating involuntary functions such as heart rate, gastrointestinal motility, and lung function. The vagus nerve carries both sensory and motor information, allowing for bidirectional communication between the brain and organs. Dysfunction or damage to the vagus nerve can lead to a range of symptoms affecting multiple organ systems.