The trigeminal nerve
The Trigeminal nerve( Fifth Or Trifacial Nerve) The trigeminal nerve is the largest cranial nerve and is the great sensory nerve of the head and face, and the motor nerve of the muscles of mastication. It emerges from the side of the pons, near its upper border, by a small motor and a large sensory root. Sensory : The three terminal branches of CN V innervate the skin, mucous membranes and sinuses of the face. Their distribution pattern is similar to the dermatome supply of spinal nerves (except there is little overlap in the supply of the divisions). Motor : Only the mandibular branch of CN V has motor fibres. It innervates the muscles of mastication: medial pterygoid, lateral pterygoid, masseter and temporalis. The mandibular nerve also supplies other 1st pharyngeal arch derivatives: anterior belly of digastric, mylohyoid, tensor veli palatini and tensor tympani. Parasympathetic Supply : The post-ganglionic neurones of par...