Cranial Nerves

Question 1

CN I

Answer 1

Olfactory Nerve

SPECIAL SENSATION: olfaction from the olfactory epithelium

TEST: Test sense of smell on both sides
Loss in frontal lobe lesions

Question 2

CN II

Answer 2

Optic Nerve

SPECIAL SENSATION: vision from the retina

Question 3

CN VIII

Answer 3

Vestibulocochlear Nerve

SPECIAL SENSATION: hearing from the cochlea

SPECIAL SENSATION: balance from the semicircular

Question 4

CN IV

Answer 4

Trochlear Nerve

SOMATIC MOTOR to the superior oblique muscle of the eye

Question 5

CN VI

Answer 5

Abducens Nerve

SOMATIC MOTOR to the lateral rectus muscle of the eye

Question 6

CN XII

Answer 6

Hypoglossal Nerve

SOMATIC MOTOR to intrinsic tongue muscles and to the genioglossus, hyoglossus and styloglossus (all muscles ending in glossis except palatoglossus)

Question 7

CN XI

Answer 7

Spinal Accessory Nerve

SOMATIC MOTOR to the sternocleidomastoid and trapezius muscles

Question 8

CN III

Answer 8

Oculomotor Nerve

SOMATIC MOTOR to most striated eye muscles including superior rectus, medial rectus, inferior rectus, inferior oblique, and levator palpebrae superiors; i.e. all extra ocular muscles except the superior oblique (CN IV) and lateral rectus (CN VI).

VISCERAL MOTOR: parasympathetic to the ciliaris and sphincter pupillae muscles. Parasympathetic preganglionic fibers synapse at the ciliary ganglion; postganglionic branches travel with branches of the opthalmic division of the trigeminal nerve (CN V).

Question 9

CN V1

Answer 9

Trigeminal Nerve, Opthalmic Division

GENERAL SENSATION from the upper face and underlying deep face including the anterior nasal cavities and the frontal, sphenoid, and ethmoid paranasal sinuses.

Question 10

CN V2

Answer 10

Trigeminal Nerve, Maxillary Division

GENERAL SENSATION from the middle face and underlying deep face including the maxillary sinus and dura mater in the anterior cranial fossa

Question 11

CN V3

Answer 11

Trigeminal Nerve, Mandibular Division

SOMATIC MOTOR to the muscles of mastication (temporalis, masseter, lateral pterygoid, medial pterygoid), and the tensor tympani, tensor veli palatini, and the anterior belly of digastricus muscles.

GENERAL SENSATION from the lower face and underlying deep face including the lower jaw, anterior two-thirds of tongue, floor of the oral cavity, mandibular teeth and dura mater in the middle cranial fossa.

Question 12

CN VII

Answer 12

Facial Nerve

SOMATIC MOTOR to the muscles of facial expression and to the stapedius, stylohyoid, and posterior belly of the digastricus muscle.

VISCERAL MOTOR parasympathetic to the lacrimal, nasal , and palatine glands. Preganglionic fibers in the greater petrosal branch synapse at the pterygopalatine ganglion; postganglionic fibers distribute with branches of CNV2.

VISCERAL MOTOR parasympathetic to the submandibular, sublingual, and minor salivary glands of the oral cavity. Preganglionic fibers in the chorda tympani branch synapse at the submandibular ganglion; postganglionic fibers distribute with branches CN V3.

GENERAL SENSATION from a small region of the external acoustic meatus and concha of external ear.

SPECIAL SENSATION taste from the palate (greater petrosal branch), and from the anterior two-thirds of the tongue (chorda tympani branch).

Question 13

CN IX

Answer 13

Glossopharyngeal Nerve

SOMATIC MOTOR to the stylopharyngeus muscle.

VISCERAL MOTOR parasympathetic to the parotid salivary gland. Preganglionic fibers in the lesser petrosal nerve synapse at the otic ganglion; postganglionic fibers distribute with the auricotemporal branch CN V3.

GENERAL SENSATION from the posterior one-third of the tongue, pharynx superior to the epiglottis, auditory tube, and middle ear.

VISCERAL SENSATION baroreception from the carotid sinus and chemoreception from the carotid body.

SPECIAL SENSATION: taste from the posterior one-third of the tongue.

Stylish parrots wear lip gloss!

Question 14

CN X

Answer 14

Vagus Nerve

SOMATIC MOTOR to muscles of the palate (levator veli palatini, musculus uvula, palatoglossus, and palatopharyngeus; i.e. all palatal muscles except tensor veli palatini), muscles of the pharynx (superior, middle, and inferior constrictors, palatopharyngeus, and salpingopharyngeus, i.e. all pharyngeal muscles except stylopharyngeus), all muscles of the larynx, and striated muscles of the upper esophagus.

VISCERAL MOTOR parasympathetic to smooth muscle and glands of the respiratory system and the gastrointestinal foregut and midgut.

GENERAL SENSATION from the larynx, pharynx inferior to the epiglottis, dura in the posterior cranial fossa, and part of the external acoustic meatus and concha of the external ear.

SPECIAL SENSATION taste from the base of the epiglottis

VISCERAL SENSATION chemoreception from the aortic body, baroreception from the aortic arch, and from some viscera including the gonads.