Cranial Nerve Functions

Hypoglossal nerve

allows the tongue to move properly.

Oculomotor Nerve (III)

controls pupil constriction and eye movement. This nerve allows us to move our eyes in response to stimuli and dilate or constrict our pupils in response to changing light conditions.

Facial nerve

controls the muscles used in smiling, frowning, and other facial expressions. It also helps produce taste in two-thirds of the tongue and allows for the sensations of touch and pain from the ear.

glossopharyngeal nerve

allows for taste on the back portion of the tongue, provides the sensations of pain and touch from the tongue and tonsils, and participates in the control of muscles used during swallowing.

Abducens nerve

allows the eyes to move away from the midline of the face. This nerve must work with cranial nerves III and IV for correct vision. If these nerves don't work together, double vision occurs.

Spinal Accessory nerve

allows the trapezius muscle and sternocleidomastoid muscle to control the movements of the head.

Trochlear nerve

also plays a role in the movement of the eyes. This nerve is especially important for looking down and looking in toward a midline object.

vestibulocochlear nerve

has separate acoustic and vestibular divisions. The acoustic portion of the nerve allows for proper hearing. The vestibular division is essential for normal balance.

Optic nerve

involved in the sense of sight. Responsible for vision, damage to this nerve can result in temporary or permanent blindness. Ophthalmologists use the location of visual disturbances to determine if damage to the optic nerve is present.

olfactory nerve

involved in the sense of smell. This nerve has access to the cerebral cortex, but does not pass through the thalamus like other cranial nerves.

Trigeminal nerve

plays a role in controlling the muscles needed for chewing. This nerve also provides the senses of pain and touch for the head and face.

Vagus nerve .

plays an important role in the human body. It controls the sensory and motor functions of the heart and glands. It also participates in the process of digestion.