Essay Question 14 - Number and Function of Cranial Nerves

Accessory Nerve XI (eleven)

It ascends alongside the spinal cord, enters the cranial cavity through the foramen magnum, then exits the cranium through the jugular foramen, bundled with the vagus and glossopharyngeal nerves. -Function: The accessory nerve controls mainly swallowing and neck and shoulder muscles. Swallowing; head, neck, and shoulder movements

Auditory nerve (8)

carries sensory information from cochlea to brain (8) (sensory)

Vagus Nerve X (ten)

-stretches from brainstem to almost all visceral organs (including heart, lungs, stomach) -carries incoming (sensory) information from peripheral nervous system to the brain -transmits outgoing motor instructions from brain to the rest of the body (10) -plays major roles in the control of cardiac, pulmonary, digestive, and urinary functions. -sensory: Taste; sensations of hunger, fullness, and gastrointestinal discomfort -motor: Swallowing, speech, deceleration of heart, broncho-constriction, gastro-intestinal secretion and motility

Trigeminal Nerve V (five)

This is the largest of the cranial nerves and the most important sensory nerve of the face. It forks into three divisions: ophthalmic (V1 ), maxillary (V2 ), and mandibular (V3 ). -Function: Touch, temperature, and pain sensations from upper face

Facial Nerve VII (seven)

This is the major motor nerve of the facial muscles. It divides into five prominent branches: temporal, zygomatic, buccal, mandibular, and cervical. -Function: Sensory: Taste Motor: Facial expression; secretion of tears, saliva, nasal and oral mucus

Olfactory Nerve I (one)

This is the nerve for the sense of smell. It consists of several separate fascicles that pass independently through the cribriform plate in the roof of the nasal cavity. It is not visible on brains removed from the skull because these fascicles are severed by removal of the brain. -Function: Smell

Optic Nerve II (two)

This is the nerve for vision. (2) (sensory)

Trochlear Nerve IV (four)

This nerve controls a muscle that directs the vision slightly downward and rotates the top of the eyeball toward the nose, especially in compensating for head movements. This is the only cranial nerve that arises from the posterior side of the brainstem. It is also unique in being the only one to completely decussate; the left trochlear nerve controls the right eye and vice versa.. -Function: Eye movements

Hypoglossal nerve (12)

allows you to swallow and talk (12) (motor)