Vagus nerve

The vagus nerve is in fact a number of nerves, but referred to as singular. The vagus nerve is the longest nerve of the autonomic nervous system and it includes both motor and sensory nerve fibers. It is the tenth cranial nerve and interfaces with the parasympathetic control of lungs, digestive tract and heart.

Myelinated axons are surrounded by Schwann cells, and are protected by layers of endoneurium. Several axons are together called a fascicle and are surrounded by the perineurium. Between the bundles, blood vessels can be seen and the whole set of nerve bundles are encapsulated by epineurium.