We all know Vegas, but what about the vagus nerve? It is the 10th out of 12 cranial nerves. Vagus, vagabond, named for its wandering nature in its function and location in the body. It is the longest of all cranial nerves and has a big parasympathetic function. We have 2 components of the nervous system. Sympathetic is our fight or flight system, necessary to engage for survival. It is also called the accelerator of the body.