Trigeminal nerve

The trigeminal nerve (the fifth cranial nerve, also called the fifth nerve or simply V) is responsible for sensation in the face. Sensory information from the face and body is processed by parallel pathways in the central nervous system.

The fifth nerve is primarily a sensory nerve, but it also has certain motor functions (biting, chewing and swallowing). These are discussed separately.

The etymology of trigeminal is often given as Latin tri (three) + gemini (twins). However, "three twins" is not the intended meaning. The Oxford English Dictionary gives the etymology as Latin trigeminus (born three at birth), which in turn derives from tri + geminus (born at the same birth). This makes a certain amount of sense, since the plural of geminus (gemini), connoting "twins," while trigeminal connotes "three parts."