Cranial Nerves, functions, exits

Question 1

CN I

Answer 1

Olfactory nerve. Sensory: Smell Exit: Cribriform plate

Question 2

CN II

Answer 2

Optic nerve Sensory: sight Exit: Optic canal

Question 3

What cranial nerves exit the skull through the superior orbital fissure?

Answer 3

CN III, IV, V (v1), VI

Question 4

CN III

Answer 4

Oculomotor nerve Motor: All eye muscles except superior oblique m and external rectus m. Also opens eye

Exit: Superior orbital fissure

Question 5

CN IV

Answer 5

Trochlear nerve Motor: Superior oblique muscle Exit: superior orbital fissure

Question 6

CN V, v1

Answer 6

v1- opthalmic division

Sensory: forehead, orbit/cornea, median/anterior nose, cranial vault (gladiator mask)

Part 1: Lacrimal n- does not cause tears

Part 2: Frontal n with 2 branches

Part 3: nasociliary n- infratrochlear n, ant/post ethmoidal nn, long/short ciliary nn.

Exits: V1- superior orbital fissure

Question 7

CN VI

Answer 7

Abducens nerve Motor: external rectus m. Exit: superior orbital fissure

Question 8

CN VII

Answer 8

Facial nerve Motor: Muscles of the face, closes eye (orbicularis oculi)

Sensory: Anterior 2/3 of tongue (taste)

Exits: Internal auditory meatus

Question 9

CN VIII

Answer 9

Vestibulocochlear nerve Sensory: inner ear Exit: internal auditory meatus

Question 10

CN IX

Answer 10

Glossopharyngeal nerve Motor: Pharyngeal musculature Sensory: Posterior part of tongue, tonsil, pharynx Exit: Jugular foramen

Question 11

CN X

Answer 11

Vagus nerve Motor and Sensory: Most of autonomic nervous system Exit: Jugular foramen

Question 12

CN XI

Answer 12

Accessory nerve Motor: sternocleidomastoid and trapezius mm Exit: jugular foramen

Question 13

CN XII

Answer 13

hypoglossal nerve Motor: Muscles of tongue Exit: hypoglossal canal

Question 14

Which cranial nerves exit through the foramen rotundum

Answer 14

CN V (v2)

Question 15

Which cranial nerves exit through the foramen ovale?

Answer 15

CN v (V3)

Question 16

Which cranial nerves exit through the internal auditory meatus?

Answer 16

CN VII and CN VIII

Question 17

Which cranial nerves exit through the jugular foramen?

Answer 17

CN IX, X, XI

Question 18

Which cranial nerve exits through the hypoglossal canal?

Answer 18

CN XII

Question 19

Which cranial nerves do not connect to the brainstem?

Answer 19

Only CN I and CN XI

Question 20

All motor fibers from trigeminal nerve travel through which division?

Answer 20

V3 division, mandibular.

Question 21

The somatosensory cells of origin for CN V are what/where? Motor cells of origin?

Answer 21

trigeminal ganglion, in periphery even though it’s on the petrous part of the temporal bone. Motor cells of origin are in the PONS of the brainstem

Question 22

CN V, v2

Answer 22

v2- Maxillary division

Sensory: Bottom lip to lower nose, then up around orbits

Sensory branches:

Superior Alveolar n- anterior, middle, posterior branches. Sensory to maxillary teeth.

Exits: foramen rotundum

Question 23

CN V, v3

• include sensory branches and what they do.

Answer 23

v3- mandibular division

Branches of sensory: BAIL

Buccal n- inside of cheek feeling, like when biting your tongue

Auriculotemporal n.- anterior external ear

Inferior alveolar n.- mandibular teeth. (becomes mental nerve after mental foramen)

Lingual n- Anterior 2/3 tongue (pain/pressure/temp, NOT taste)

*Also lower lip, chin, cranial vault, unconcious jaw-joint sensation

Motor: chew (temporalis, masseter, medial and lateral pterygoid mm), open mouth WIDE (anterior belly of digastric), swallow (mylohyoid, ant. belly of digastric), tensor veli palatini m (soft palate), dampen noise (tensor tympani)

Exits: foramen ovale

Question 24

Name the nerve brances and what foramen they come out of

Answer 24

1. supraorbital branch of v1 (superior orbital foramen)
2. supratrochlear branch of v1
3. zygomatic branch of v2
4. zygomatic branch of v2
5. infraorbital branch of v2 (infraorbital foramen)
6. buccal branch of v3
7. mental branch of v3 (mental foramen)

Question 25

Nasal cavity nerves (3). what do they come off of?

Answer 25

1. internal nasal nerve, which is a continuation of the ant. ethmoidal n. (v1)
2. nasopalatine n- septal side, comes from v2. Sensory for anterior gums.
3. posterior lateral nasal n- comes from v2

Question 26

What are the palatine nerves, what do they do, and where do they come from?

Answer 26

1. Nasopalatine n- Anterior gums and hard palate
2. Greater palatine n- most of hard palate/gums.
3. Lesser palatine n- Anterior part of SOFT PALATE

Question 27

what branches and from what bigger branch are these areas innervated by? What major arteries/nerves/structures do they travel with?

Answer 27

1. v1 branch- travels with internal carotid artery branches
2. v2 meningeal branch- travels with middle meningeal a
3. v3 meningeal branch- travels with middle meningeal a
4. v1 branch- travels along tentorium cerebelli
5. spinal nerves C2 and C3- some brr travel with or on CN X or XII. Supply vessels and dura in posterior cranial fossa.