Nervous System - Cranial Nerves

Question 1

CN I

Answer 1

Olfactory N.
special sense of smell

Location: Olfactory bulb + tract inferior/medial to Frontal lobe. Hair-like nerves come from bulb to pass thru Cribiform plate of ethmoid bone. Lateral of Crista Gali

Question 2

CN II

Answer 2

Optic N. (carries visual info fr one eye only)

attached to posterior aspect of eyeball. receives info fr one Retina and transports posteriorly to Occipital Lobe. Pass thru Optic Canal in Sphenoid bone

Question 3

CN III

Answer 3

Oculomotor N. (oculo=eye; eye mvmt.)

originates in cerebral peduncles, moves anteriorly to pass thru Superior orbital fissure to reach the eye.
Muscles: Superior, Inferior, Medial, Inferior Oblique, Levator Palpebrae Superioris (eyelid)

Parasympathetic: constriction of pupil, + lens accommodation (maintain focus on object)

Question 4

CN IV

Answer 4

Trochlear N.
1/6 extraocular muscle: Superior Oblique Muscle

Originates posteriorly of brainstem, travels a long way to pass thru Superior orbital fissure

Question 5

CN V

Answer 5

Trigeminal N. (“3 twins” V1, V2, V3)
General Somatic Afferent fibers innervates structures of viscerocranium (like dura mater), skin covering face, mandibular+maxillary teeth, mucosal lining of oral + nasal cavity

“Standing Room Only” indicates first letter of foramen each divisioin enters: originates lateral side of Pons. V1 passes thry Superior Orbital Fissure, V2 passes Rotundum Foramen, V3 passe thru Ovale Foramen

Question 6

CN VI

Answer 6

Abducens N.
1/6 extraocular muscle:
Lateral Rectus

originates lateral to dorsal mid Pons, in the floor of 4th ventricle via Suborbital Fissue

Question 7

CN VII

Answer 7

Facial N.
(motor, sensory, + parasympathetic)

Originates in Posterior Cranial Fossa, pass thru Internal Acoustic Meatus, pass thru Stylomastoid Foramen, penetrate/pass thru Parotid Gand (salivary gland) where it branches out superiorly, inferiorly, and anteriorly to target organs

Question 8

CN VIII

Answer 8

Vestibulocochlear N.
special sense of hearing + balance

double barreled appearance because of 2 nerves attached together

Vestubular N. attaches to Semicircular Canals (in ear)

Cochlear N. to Cochlea responsible for hearing

originates pontomedullary junction of brainstem, passes thru Internal Acoustic Meatus, terminates in temporal bone, in our ear

Question 9

CN IX

Answer 9

Glossopharyngeal N.
motor/sensory/parasympathetic

lateral aspect of brainstem thru jugular foramen,

Question 10

CN X

Answer 10

Vagus N.
motor/sensory/parasympathetic
largest CN

In posterior cranial fossa, pass thru Jugular Foramen, and descends along Corotid Artery

Question 11

CN XI

Answer 11

Accessory N.
Sternocleidmastoid (SCM) + Trapezius muscles

2 points of origin (cervical spinal cord + brainstem) ascends up Foramen Magnum, then laterally to Jugular Foramen, and send branches to 2 muscles

Question 12

CN XII

Answer 12

Hypoglossal N.
extrinsic (outside of tongue) + intrinsic (the tongue itself) muscles

travels down and thru hypoglossal canal near foramen magum, descend parallel to Carotid Artery to tongue.

Question 13

mnemonic device for CN names

Answer 13

O, O, O, To Touch And Feel Very Good Velvet At Home

Question 14

mnemonic device for CN

sensory, motor, or both?

Answer 14

Some Say Marry Money, But My Brother Says “Big Brains Matter More”

Question 15

Parasympathetic/Autonomic CN

Answer 15

CN III, VII, IX, X

Question 16

Optic Chiasm

Answer 16

crossing-like structure along visual pathway where signals from both eyes communicate w each other

Question 17

Tochlea

Answer 17

tendon in eye for superior oblique

Question 18

Superior Oblique

Answer 18

muscle on eye that helps mvmt inferio-laterally

Question 19

Trigeminal V1 Division

Answer 19

Opthalmic Division (Sensory) 
cutaneous sensation to forehead, bridge of nose, and surface of eye

Question 20

Trigeminal V2 Division

Answer 20

Maxillary Division
(Sensory)
cutaneous sensation to cheek, face, upper lip, nasal + oral cavities, and upper teeth

Question 21

Trigeminal V3 Division

Answer 21

Mandibular Division (Motor/Sensory)

General Somatic Afferent: cutaneous ear, face, jaw, lower lip, inside oral cavity, tongue

Somatic Branchial Efferent fibers innervate head + neck muscles for mastication:
Masseter, Temporalis, Medial + Lateral Pterygoid, Mylohyoid Muscle, Tensory Tympani Muscle, Tensor Veli Palatani Muscle

Question 22

CN VII - Sensory

Answer 22

innervates anterior 2/3 of tongue for TASTE

located in Geniculate Ganglion located in facial canal of temporal bone

Question 23

CN VII - Motor

Answer 23

facial expression

Originates in Tegmentum of the Pons

Question 24

CN VII - Parasympathetic

Answer 24

Sublingual + submandibular glands (for salivation), Lacrimal gland (tear)

Originates from Superior Salivary nucleus of the pons

Question 25

Semicircular Canal

Answer 25

innervated by VIiI, the vestibular portion.

Located in middle ear as loops that contain liquid for equilibrium

Question 26

CN IX Sensory

Answer 26

General + special sense of taste to posterior 1/3 of tongue,
sensations of pharynx,
monitors blood pressure + oxygen levels to brain on Carotid Sinus + Carotid Body (blood vessels)

Question 27

CN IX Motor

Answer 27

Stylopharyngeus Muscles assist to elevating the harynx

Question 28

CN IX Parasympathetic

Answer 28

innervates Parotid Glandsfor salivation

Question 29

Jugular Foramen Mnemonics

Answer 29

if you cut a jugular, then call “911”

CN 9, CN 10, CN 11

Question 30

CN X - Motor

Answer 30

soft palate muscles, pharyngeal + laryngeal muscles

to help swallow, modulate voice of larynx,

Question 31

CN X - Sensory

Answer 31

General sense of inferior pharynx + larynx, thoracic + abdominal organs

Question 32

CN X - Parasympathetic

Answer 32

Thoracic + abdominal viscera up to 2/3 of transverse colon

Question 33

Foramens of CN

Answer 33

1 Cribriform Plate
2 Optic Canal
3 Superior Orbital Fissure
4 Superior Orbital Fissure
5
5.1 Superior Orbital Fissure
5.2 Foramen Rotundum
5.3 Foramen Ovale
6 Superior Orbital Fissure
7 Internal Acoustic Meatus
8 Internal Acoustic Meatus
9-11 Jugular Foramen
12 Hypoglossal Canal