Cranial Nerves

How many cranial nerves are there?

12

How are the cranial nerves numbered?

from anterior to posterior on the ventral surface of the brain

What is cranial nerve I?

olfactory nerve

Where do the axons of the olfactory nerve pass through?

the cribriform plate of the ethmoid bone

Does the olfactory nerve carry sensory information, motor information, or both?

sensory information

What is cranial nerve II?

optic nerve

Does the optic nerve carry sensory information, motor information, or both?

sensory

What is cranial nerve III?

oculomotor

Does the oculomotor nerve carry sensory information, motor information, or both?

motor

What is the origin of the olfactory nerve?

unmyelinated axons of neurons whose cell bodies are located in the olfactory epithelium in the roof of the nasal cavity

What is the course of the olfactory nerve?

axons form bundles that penetrate the holes in the cribriform plate of the ethmoid bone and end in the olfactory bulb

Where is the destination of the olfactory nerve?

medial temporal lobe and structures of the limbic system

What is the function of the olfactory tract?

sense of smell

What is the origin of the optic nerve?

myelinated axons of neurons int he posterior eye

What is the course of the optic nerve?

the two optic nerves meet and form an X known as the optic chiasma, where some of the axons decussate

What is the destination of the optic nerve?

axons from the optic chiasma go to structures in the occipital lobe

What is the function of the optic nerve?

vision

What is the origin of the vestibulocochlear nerve?

two separate nerves that originate in the inner ear and share a common epineurium

What is the course of the vestibulocochlear nerve?

fibers from the two nerves fuse shortly after they leave the temporal bone to become one nerve

What is the destination of the vestibular nerve?

axons terminate in the cerebellum and in nuclei in the medulla oblongata

What is the destination of the cochlear nerve?

axons travel to the medulla oblongata and terminate in auditory cochlear areas

What is the function of the vestibular nerve?

concerned with balance and equilibrium

What is the function of the cochlear nerve?

responsible for sense of hearing

What is the origin of the oculomotor nerve?

arises from the superior and lateral portion of the midbrain

What is the destination of the oculomotor nerve?

extrinsic eye muscles and smooth muscles of the eye

What is the function of the oculomotor nerve?

moving the eye, opening the eye, constricting the pupil, and changing the lens shape

What is the origin of the trochlear nerve?

originates from the inferior portion of the midbrain

What is the destination of the trochlear nerve?

superior oblique muscles of the eye

What is the function of the trochlear nerve?

moves eye medially and inferiorly

What is the origin of the abducens nerve?

in the pons

What is the destination of the abducens nerve?

lateral rectus muscle of the eye

What is the function of the abducens nerve?

abducts the gaze when it turns the eye laterally

Which three muscles are involved in extrinsic muscle contraction and movement of the eye?

oculomotor, trochlear, and abducens

What is the origin of the accessory nerve?

cranial component from the medulla and a spinal component from the cervical spinal cord

What is the destination of the cranial component of the accessory neuron?

innervates certain muscles of the larynx

What is the destination of the spinal component of the accessory nerve?

innervates the trapezius and sternocleidomastoid muscles

What is the function of the accessory nerve?

cranial component helps with speech, the spinal component moves the head and shoulders

What is the origin of the hypoglossal nerve?

arises from the inferior most part of the medulla

What is the destination of the hypoglossal nerve?

lies inferior to the tongue. Innervates most intrinsic and extrinsic muscles of the tongue

What is the function of the hypoglossal nerve?

plays a role in taste sensation

What is the origin of the trigeminal nerve?

motor portion originates at the midbrain and pons junction, sensory portion from sensory receptors around the face

What is the course of the trigeminal nerve?

trigeminal ganglion houses the cell bodies of its sensory neurons. Anterior to this, it splits into three branches

What is the destination of the trigeminal nerve?

all three branches have sensory fibers that terminate in the primary somatosensory cortex. Mandibular nerve has motor fibers that terminate at the muscles of mastication

What is the sensory function of the trigeminal nerve?

detects facial sensation

What is the sensory function of the ophthalmic nerve?

supplies the skin over much of the scalp, forehead, around the eyes, anterior nose, and structures of the eye

What is the sensory function of the maxillary nerve?

supply the skin over the middle of the face

What is the sensory function of the mandibular nerve?

supply the skin of the chin and the lateral part of the face

What is the motor function of the mandibular nerve?

supply the masseter and temporalis muscles

What is the origin of the facial nerve?

motor portion originates in nuclei in the pons and medulla, sensory portion from the tongue, external ear, palate, and nasal cavity

What is the course of the facial nerve?

several ganglia house cell bodies of the facial nerves sensory route, the largest being the geniculate ganglion

What is the sensory function of the facial nerve?

taste sensation of the anterior 2/3 of the tongue and somatic sensation from the external ear, palate, and nasal cavity

What is the motor function of the facial nerve?

supply muscles of facial expression and other facial muscles

What is the sensory destination of the facial nerve?

various somatosensory areas of the cerebral cortex

What is the motor destination of the facial nerve?

innervate the muscles of facial expression as well as several other facial and neck muscles

What are the five branches of the motor root of the facial nerve?

temporal, zygomatic, buccal, mandibular, and cervical (To Zanzibar By Motor Car)

What is the origin of the glossopharyngeal nerve?

motor neurons originate in the nuclei in the medulla, sensory neurons originate in the tongue, pharynx, around the ear, and in blood vessels of the neck

What is the course of the glossopharyngeal nerve?

cell bodies of its sensory neurons are located in two ganglia: superior and inferior ganglia

What is the destination of the glossopharyngeal nerve?

innervates the tongue and pharynx

What is the function of the sensory portion of the glossopharyngeal nerve?

sense of taste of the posterior 1/3 of the tongue, innervates the external ear alongside the facial nerve, provide sensation for the posterior pharynx and surrounding structures

What is the motor function of the glossopharyngeal nerve?

supply a muscle around the pharynx that is responsible for swallowing movements

What is the origin of the vagus nerve?

the motor neurons originate from the brain at the medulla. Sensory neurons originate around the tongue, pharynx, skin of the ear, and certain blood vessels of the neck

What is the course of the vagus nerve?

cell bodies of the sensory neurons are housed in the superior and inferior ganglia

What is the destination of the vagus nerve?

most widely distributed nerve. Innervates the throat and anterior neck, and nearly all the thoracic and abdominal viscera

What is the sensory function of the vagus nerve?

serve the skin around the ear, taste sensations, detect the CO2 concentration

What is the motor function of the vagus nerve?

supply muscles surrounding the pharynx and larynx important in speaking and swallowing

What nerve is bells palsy usually associated with?

facial nerve

What is cranial nerve VIII?

vestibulocochlear nerve

What is cranial nerve IV?

trochlear nerve

What is cranial nerve VI?

abducens nerve

What is cranial nerve XI?

accessory nerve

What is cranial nerve XII?

hypoglossal nerve

What is cranial nerve V?

trigeminal nerve

What is cranial nerve VII?

Facial nerve

What is cranial nerve IX?

glossopharyngeal nerve

What is cranial nerve X?

vagus nerve

Does the trochlear nerve carry sensory information, motor information, or both?

Motor

Does the trigeminal nerve carry sensory information, motor information, or both?

both

Does the abducens nerve carry sensory information, motor information, or both?

Motor

Does the facial nerve carry sensory information, motor information, or both?

both

Does the vestibulocochlear nerve carry sensory information, motor information, or both?

sensory

Does the glossopharyngeal nerve carry sensory information, motor information, or both?

Both

Does the vagus nerve carry sensory information, motor information, or both?

Both

Does the accessory nerve carry sensory information, motor information, or both?

Motor

Does the Hypoglossal nerve carry sensory information, motor information, or both?

Motor