Cranial Nerves The “FACE” of Cranial Nerves
I Olfactory II Optic III Oculomotor IV Trochlear V Trigeminal VI Abducens VII Facial VIII Acoustic IX Glossopharyngeal X Vagus XI Spinal Accessory Xii Hypoglossal Cranial Nerves
Cranial Nerves • CN I – Olfactory Nerve • Sensory nerve • Transmits the sense of smell from the nasal cavity. • This nerve has access to the cerebral cortex, but does not pass through the thalamus like other cranial nerves. REMEMBER: Thalamus acts like a switchboard relaying info to parts of brain.
How good is your sense of smell? Can you tell what flavor it is? • While pinching your nose closed and closing your eyes, eat a jelly bean.
Cranial Nerves • CN II – Optic Nerve • Special Sensory • Transmits visual signals from the retina of the eye to the brain
Cranial Nerves • CN III – Occulomotor Nerve • Motor nerve • It controls the muscles that allow for visual tracking and fixation by the eye • Dilate or constrict our pupils in response to changing light conditions. • Raise our eyelids
Cranial Nerves • CN IV – Trochlear Nerve • Motor nerve • Plays a role in the movement of the eyes. • Especially important for looking down and looking in toward a midline object.
Cranial Nerves • CN V – Trigeminal Nerve • Mixed nerve: sensory and motor • Contains the sensory fibers of pain and touch from the face • Also controls muscles involved in mastication (chewing)
Cranial Nerves • CN VI – Abducens Nerve • Motor nerve • Stimulates the lateral eye muscle to turn the eye outward. • Longest of all cranial nerves; more easily injured. • Nerve crosses to both eyes. If one side injured, eyes do not move together causing double vision or lazy eye.
Cranial Nerves • CN VII – Facial Nerve • Mixed nerve: motor and sensory • 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 sensations of touch and pain from the ear.
Cranial Nerves • CN VIII – Acoustic (Vestibulocochlear) • Sensory nerve • Consists of two separate parts. • “Cochlear” nerve carries the sensation of hearingfrom the ear to the brain. • “Vestibular “ nerve carries information about position and movements of the head = balance.
Cranial Nerves • CN IX – Glossopharyngeal Nerve • Mixed nerve: sensory and motor • Allows for taste on the back portion of the tongue • Provides sensations of pain and touch from the tongue and tonsils • participates in the control of muscles used during swallowing.
Cranial Nerves • CN X – Vagus Nerve • Mixed nerve: sensory and motor • It controls the sensory and motor functions of the heart and glands. • It also participates in the process of digestion. • Only nerve that extends out into the body.
Cranial Nerves • CN XI – Spinal Accessory Nerve • Motor nerve • Allows the trapezius muscle and sternocleidomastoid muscle to control the movements of the head= tilt your head
Cranial Nerves • CN XII – Hypoglossal Nerve • Motor nerve • Allows the tongue to move properly; helps in speech and moving food to back of mouth for swallowing.