Cranial Nerves

Question 1

Are the cranial nerves considered part of the CNS or PNS?

Answer 1

PNS

Question 2

Name cranial nerve I

Answer 2

Olfactory

Question 3

Name cranial nerve II

Answer 3

Optic

Question 4

Cranial nerve III

Answer 4

Occulomotor

Question 5

Cranial nerve IV

Answer 5

Trochlear

Question 6

Cranial nerve V

Answer 6

Trigeminal

Question 7

Cranial nerve VI

Answer 7

Abducens

Question 8

Cranial nerve VII

Answer 8

Facial

Question 9

Cranial nerve VIII

Answer 9

Vestibulocochlear

Question 10

Cranial nerve IX

Answer 10

Glossopharyngeal

Question 11

Cranial nerve X

Answer 11

Vagus

Question 12

Cranial nerve XI

Answer 12

Accesory

Question 13

Cranial nerve XII

Answer 13

Hypoglossal

Question 14

Name the sensory only cranial nerves? Hint: there are only 2.

Answer 14

Olfactory and Optic

Question 15

Name the motor only cranial nerves? Hint: there are 5.

Answer 15

Oculomotor, Trochlear, Abducens, Accessory and Hypoglossal

Question 16

Name the cranial nerves with both motor and sensory function. Hint there are 5.

Answer 16

Trigeminal, Facial, Vestibulocochlear, Glossopharyngeal, and Vagus

Question 17

Name the divisions of the Trigeminal nerve.

Answer 17

Ophthalmic, Maxillary and Mandibular.

Question 18

Name the divisions of the Facial nerve.

Answer 18

Temporal, Zygomatic, Buccal, Mandibular, Cervical

Question 19

What is the pathway of the Olfactory nerves?

Answer 19

The cribriform plate of the ethmoid bone. Synapse happens in the olfactory bulb, the olfactory tract runs beneath the frontal lobe to enter the cerebral hemispheres and terminate in the primary olfactory cortex.

Question 20

What is the pathway of the Optic Nerves?

Answer 20

Passing through the optic canal of the orbit, and converging fibers at the optic chiasma, then continue on as optic tracts that enter the thalamus, and synapse there. Thalamic fibers run to the occipital cortex, where visual interpretation occurs.

Question 21

What is the pathway of the Oculomotor nerves?

Answer 21

Fibers extend from the ventral midbrain, passing through the superior orbital fissure to the eye.

Motor fibers to 4 of the 6 extrinsic eye muscles.

Sensory fibers runs from the same 4 extrinsic muscles for proprioception.

Parasympathetic motor fibers to sphincter of pupillae which cause constriction.

Question 22

What are the 4 extrinsic eye muscles that the Oculomotor innervates?

Answer 22

Inferior oblique
Superior rectus
Inferior rectus
Medial rectus

Question 23

Which nerve innervates the superior oblique eye muscle?

Answer 23

Trochlear nerve

Question 24

Which nerve innervates the lateral rectus eye muscle?

Answer 24

Abducens

Question 25

What is the pathway of the Trochlear nerves?

Answer 25

Motor fibers emerge from dorsal midbrain and course ventrally around midbrain to enter the superior orbital fissure along with the oculomotor nerves.

Question 26

What is the pathway of the Ophthalmic division of the trigeminal nerves?

Answer 26

Sensory nerves run through the superior orbital fissure to the pons. Conveying impulses from skin of the anterior scalp, upper eyelid, nose and nasal cavity mucosa, cornea, and lacrimal gland.

Question 27

What is the pathway of the Maxillary division of the trigeminal nerves?

Answer 27

Sensory fibers run through the foramen rotundum to the pons. Conveying sensory impulses from nasal cavity mucosa, palate, upper teeth, skin of cheek, upper lip, lower eyelid.

Question 28

What is the pathway of the Mandibular division of the trigeminal nerves?

Answer 28

Fibers run through the foramen ovale.

Sensory impulses from anterior tongue (except taste buds), lower teeth, skin of chin, temporal region of scalp.

Motor fibers supply muscles of mastication.

Question 29

What is the pathway of the abducens nerves?

Answer 29

Motor fibers leave the pons and enter the orbit via the superior orbital fissure to supply the lateral rectus muscles.

Question 30

What is the pathway of the Facial nerves?

Answer 30

Fibers issue from the pons, pass through the temporal bone via teh internal acoustic meatus, and run within bone (and through inner ear cavity) before emerging through stylomastoid foramen. Then course to lateral aspects of the face.

Motor fibers supply skeletal muscles of face (except the chewing muscles).

Sensory impulses from taste buds of anterior two-thirds of tongue; cell bodies of these sensory neurons are in geniculate ganglion.

Question 31

Paralysis of facial muscles on affected side and partial loss of taste sensation is known symptom of what dysfunction?

Caused by inflamed and swollen facial nerve, possibly due to herpes simplex 1 viral infection. Lower eyelid droops, corner of mouth sags, tears dip continuously from the eye as it cannot close.

Answer 31

Bell’s palsy