Trigeminal Nerves (V)
The "trigeminal nerves" are the fifth pair of cranial nerves and stem
from the pons (which is located at the base of the brain stem). These are
"mixed" nerves, made up of sensory and motor nerves. Each sensory
component has three large branches: (1) the "ophthalmic division" whose
fibers bring impulses to the brain from the surface of the eye, the tear
gland, and the skin of the scalp, forehead, and upper eyelid, (2) the
"maxillary division" which carries impulses from the upper teeth, upper
gum, upper lip, and the mucous lining of the palate and the skin of the
face, and (3) the "mandible division", which has both motor and sensory
fibers. The sensory branches carry impulses from the scalp behind the ear,
the skin of the jaw, the lower teeth, the lower gum, and the lower lip.
The motor branches supply muscles for chewing and certain muscles on the
floor of the mouth. These nerves are numbered "V", because they are the
fifth pair of cranial nerves from the front of the brain.