Unit 3: PNS - Cranial Nerves

foramina of the cranial base

Where do the cranial nerves enter and exit the cranial cavity?

sensory (afferent)

carries nerve fibers from sensory receptors to the brain

motor (efferent)

carries nerve fibers from the brain to effector tissues (muscles)

yes

Can some cranial nerves contain a combination of both sensory and motor nerve fibers?

sensory

Is the Olfactory Nerve (CN I) sensory or motor?

smell

What does the Olfactory Nerve (CN I) convey signals for?

nasal mucosa

Where does the Olfactory nerve ending reside?

chemoreceptors for scent molecules

What do the Olfactory nerve endings serve as in the nasal mucosa?

foramina of the cribriform plate

Where do the individual Olfactory nerve fibers enter?

olfactory bulb, olfactory tracts

Once through the foramina of the cribriform plate, the olfactory nerve fibers "synapse" in the ___ ___ and extend posteriorly as the ___ ___.

temporal lobes, primary olfactory cortex

The olfactory nerves lead to the ___ ___ of the brain which contain the ___ ___ ___ for interpretation of smell.

sensory

Is the Optic nerve (CN II) sensory or motor?

sight

What does the Optic nerve (CN II) convey signals for?

optic canals

Where do optic nerves enter the cranial cavity?

optic radiations, occipital lobe

The optic nerves course posteriorly, "synapsing" on the thalamus and then continue as the ___ ___ which lead to the __ __ of the brain (the primary visual cortex) for interpretation of the sense of sight.

motor

Is the Oculomotor nerve (CN III) sensory or motor?

Muscles of eye movement

What do the Oculomotor nerves convey motor nerves for?

ventral midbrain, superior orbital fissure

Where does the oculomotor nerve originate and exit?

intrinsic and extrinsic muscles of eye movement

What does the Oculomotor nerve innervate?

Intrinsic muscles

Involved with dilation and contraction of the iris

Extrinsic muscles

What type of muscle moves the eyes?

Medial rectus, Superior rectus, Inferior rectus, Inferior oblique

What is included in Extrinsic muscles of Oculomotor nerve (CN III)?

motor

Is the Trochlear nerve (CN IV) sensory or motor?

muscles of eye movement

What do the Trochlear nerves convey motor nerves for?

dorsal midbrain, superior orbital fissure

Where does the Trochlear nerve originate and exit?

Superior oblique (extrinsic eye movement)

What does the Trochlear nerve innervate

Opthalmic, Maxillary, Mandibular

What are the 3 branches of the Trigeminal nerve?

both

Is the Trigeminal nerve sensory or motor?

muscles of mastication, face and head

What does the Trigeminal nerve provide innervation and cutaneous innervation for?

superior orbital fissure

Where does the Ophthalmic branch exit?

lacrimal glands, skin of the forehead, nose, upper eyelids

What does the Ophthalmic branch give innervation and cutaneous innervation to?

foramen rotundum

Where does the Maxillary branch exit?

superior dental plexus, lateral scalp, cheek, lower eyelid, lateral nose and upper lip

What does the Maxillary branch give innervation to?

foramen ovale

What does the Mandibular branch exit?

inferior alveolar nerve

What does the Mandibular nerve give off?

inferior dental plexus

What does the inferior alveolar nerve give innervation to?

skin and mucosa of the cheek, anterior 2/3 of the tongue for general sensation, muscles of mastication

What do the other branches of the Mandibular nerve supply sensation to?

inferior aspect of the pons, superior orbital fissure

Where does the Abducent nerve originate and exit?

Lateral rectus (extrinsic muscle of eye movement)

What does the Abducent nerve innervate?

Lateral Rectus

Involved with the action of "abducting" the eye

Internal acoustic meatus

Where does the Facial nerve (CN VII) exit?

both

Is the Facial nerve (CN VII) sensory or motor?

anterior 2/3 of the tongue for taste

What does the Facial nerve give off sensory branches to?

side of the face, muscles of facial expression

What do the 5 branches of the Facial nerve supply sensory innervation/motor innervation to?

sensory

Is the Vestibulocochlear neave (CN VIII) sensory or motor?

hearing and balance

What does the Vestibulocochlear nerve convey sensory information for?

Vestibular branch, Cochlear branch

What are the 2 divisions of the Vestibulocochlear nerve?

Vestibular branch

Courses from the semicircular canals and is responsible for balance

Cochlear branch

Courses from the cochlea and is responsible for the sense of hearing

internal acoustic meatus

Where does the Vestibulocochlear nerve enter?

both

Is the Glossopharyngeal (CN IX) sensory or motor?

jugular foramen

Where does the Glossopharyngeal nerve exit?

Muscles of the pharynx

What does the Glossopharyngeal nerve innervate?

Posterior 1/3 of the tongue for taste and general sensation

Where does the Glossopharyngeal nerve ends?

Jugular foramen

Where does the Vagus nerve exit?

Both

Is the Vagus nerve sensory or motor?

musculature of the larynx and pharynx, heart, major viscera of the abdomen

What does the Vagus nerve give innervation to?

Jugular Foramen

Where does the Accessory nerve exit?

motor

Is the Accessory nerve sensory or motor?

Trapezius, Sternocleidomastoid

What does the Accessory nerve innervate?

Hypoglossal canal

Where does the Hypoglossal nerve exit?

motor

Is the Hypoglossal nerve sensory or motor?

muscles of tongue movement

What does the Hypoglossal nerve convey motor nerve fibers to?