Neuroanatomy: Cranial Nerves

Front 1

(I) Olfactory
Type:

Back 1

Sensory

Front 2

(I) Olfactory
Function:

Back 2

smell

Front 3

(I) Olfactory
Clinical Exam:

Back 3

various odors applied to each nostril

Front 4

(I) Olfactory
Typical Dysfunction

Back 4

Anosmia: Loss of smell

Front 5

(II) Optic
Type:

Back 5

sensory

Front 6

(II) Optic
Funciton:

Back 6

vision

Front 7

(II) Optic
Clinical Exam:

Back 7

visual acuity, visual fields

Front 8

(II) Optic
Typical Dysfunction

Back 8

Anopia- loss of vision

Front 9

(III) Oculomotor
Type:

Back 9

motor

Front 10

(III) Oculomotor
Function of LMN:

Back 10

-innervates 4 extraocular muscles: superior, inferior, and medial recti, and inferior oblique m.
-striated m. of eyelid: levator palpebrae superioris

Front 11

(III) Oculomotor
Function of Parasympathetic:

Back 11

-pupilary constriction: sphincter pupillae m
-accommodation of lens for near vision: ciliary body m.

Front 12

(III) Oculomotor
Clinical Exam:

Back 12

Sym: Movements of eyes (medial and vertical)
Movements of upper eyelid

Parasym: Reaction to light

Front 13

(III) Oculomotor
Typical Dysfunction:

Back 13

Sym: diplopia, lateral strabisumus, ptosis

Parasym: mydriasis, disruption of near vision, accomodation

Front 14

(IV) Trochlear
Type:

Back 14

motor

Front 15

(IV) Trochlear
Function:

Back 15

LMN: innervates superior oblique m.

Front 16

(IV) Trochlear
Clinical Exam:

Back 16

Downward movement of adducted eye

Front 17

(IV) Trochlear
Typical Dysfunction:

Back 17

Diplopia
Difficulty walking downstairs
Compensatory head tilt leading to neck problems

Front 18

(V) Trigeminal
Type:

Back 18

mixed

Front 19

(V) Trigeminal
Function of Sensory:

Back 19

most of face including: skin, cornea, sinuses, most of oral cavity, teeth, anterior two-thirds of the tongue, muscles of face and jaws, proprioception from TMJ

Front 20

(V) Trigeminal
Function of LMN:

Back 20

muscles of mastication, tensor tympani, tensor palati, myolohyoid, anterior belly of digastric m.

Front 21

(V) Trigeminal
Clinical Exam of Sensory:

Back 21

Face: light touch, 2-point tactile, pinprick, cold test tubes

Corneal reflex: touch cornea

Jaw jerk reflex: tapping chin

Front 22

(V) Trigeminal
Clinical Exam of LMN:

Back 22

Jaw movement

Front 23

(V) Trigeminal
Typical Dysfunction of Sensory:

Back 23

decreased senstivity of numbness of face
Trigeminal neuralgia: brief attacks of severe pain

Front 24

(V) Trigeminal
Typical Dysfunction of LMN:

Back 24

weakness and wasting of jaw muscles
asymmetric chewing

Front 25

(VI) Abducens
Type:

Back 25

Motor

Front 26

(VI) Abducens
Function:

Back 26

LMN innervates lateral rectus m.

Front 27

(VI) Abducens
Clinical Exam:

Back 27

Lateral movement of eyes

Front 28

(VI) Abducens
Typical Dysfunction

Back 28

Diplopia
Medial strabismus when looking to side of weakness

Front 29

(VII) Facial
Type:

Back 29

Mixed

Front 30

(VII) Facial
Function of Sensory:

Back 30

Sensation from the skin of the external ear canal
Taste from anterior two-thirds of the tongue

Front 31

(VII) Facial
Function of LMN:

Back 31

LMN: innervates muscles of facial expression, stapedius, stylohyoid, posterior belly of digastric muscle, CORNEAL REFLEX

Front 32

(VII) Facial
Function of Parasym:

Back 32

innervates lacrimal gland, sublingual glands, submandibular glands

Front 33

(VII) Facial
Clinical Exam for Sensory:

Back 33

Bitter, sweet, and sour taste tests

Front 34

(VII) Facial
Clinical Exam for LMN:

Back 34

Facial movements and expression, corneal reflex, and blinking

Front 35

(VII) Facial
Typical Dysfunction of Sensory:

Back 35

Loss of taste over anterior two-thirds of tongue

Front 36

(VII) Facial
Typical Dysfunction of LMN:

Back 36

Facial paralysis, difficulty closing eye or raising eyebrow, disruption of corneal reflex
Hyperacusis-increased sensitivity to loud sounds

Front 37

(VII) Facial
Typical Dysfunction of Parasympathetic

Back 37

Dry eye, decreased saliva

Front 38

(VIII) Vestibulocochlear
Type:

Back 38

Sensory

Front 39

(VIII) Vestibulocochlear
Function:

Back 39

Hearing
Sense of motion and position of head

Front 40

(VIII) Vestibulocochlear
Clinical Exam:

Back 40

Rinnes and Webers
Caloric Test
Irrigate ear canal with hot or cold water

Front 41

(VIII) Vestibulocochlear
Typical Dysfunction:

Back 41

Deafness
Tinnitus- sensation of noise in ear
Loss of equilibrium
Spacial disorientation and Vertigo
Nystagmus-oscillating eye movements

Front 42

(IX) Glossopharyngeal
Type:

Back 42

Mixed

Front 43

(IX) Glossopharyngeal
Function of Sensory:

Back 43

Taste and general sensation from posterior third of tongue,
Sensation from oropharynx & middle ear,
Gag Reflex, and Carotid sinus reflex

Front 44

(IX) Glossopharyngeal
Function of LMN:

Back 44

Innervates stylopharyngeus muscle

Front 45

(IX) Glossopharyngeal
Function of Parasym:

Back 45

Innervates parotid gland

Front 46

(IX) Glossopharyngeal
Clinical Exam for Sensory:

Back 46

Test for taste on back of tongue,
Test for gag reflex by touching walls of pharynx

Front 47

(IX) Glossopharyngeal
Typical Dysfunction of Sensory:

Back 47

Loss of sensation in back of throat, Loss of gag reflex,
Spasms of pain in posterior pharynx, Fall in blood pressure

Front 48

(X) Vagus
Type:

Back 48

Mixed

Front 49

(X) Vagus
Function of Sensory:

Back 49

Sensation from lower pharynx, larynx, and upper esophagus (*Spinal tract and nucleus of V),
Taste from epiglottis (*Nucleus solitarius*)
Involved in visceral reflexes

Front 50

(X) Vagus
Function of LMN:

Back 50

Innervates skeletal muscles of larynx, pharynx, palate, and upper esophagus
*Nucleus ambiguus*

Front 51

(X) Vagus
Function of Parasym:

Back 51

Innervates smooth muscle and glands of viscera of neck, thorax (lungs), and abdomen (stomach, small intestines, through transverse colon), innervates cardiac muscle (heart),
Carotid Sinus Reflex
*Dorsal motor nucleus* is parasym
*Fasciculus solitarius* interneurons for visceral reflexes

Front 52

(X) Vagus
Clinical Exam for LMN:

Back 52

Observe palate and vocal cords in phonation,
Test palate for gag reflex

Front 53

(X) Vagus
Typical Dysfunction of LMN:

Back 53

Ipsilateral findings:
Hoarseness,
Dysphonia
Paralysis of vocal cord,
Drooping of soft palate
Dysphagia, and Loss of gag reflex

Front 54

(XI) Spinal Accessory
Type:

Back 54

Motor

Front 55

(XI) Spinal Accessory
Function:

Back 55

LMN: innervates trapezius and sternocleidomastoid muscles

Front 56

(XI) Spinal Accessory
Clinical Exam:

Back 56

Movement strength & Bulk of neck and shoulder muscles

Front 57

(XI) Spinal Accessory
Typical Dysfunction:

Back 57

Wasting of neck with muscle rotation,
Inability to shrug,
Low shoulder on weak side

Front 58

(XII) Hypoglossal
Type:

Back 58

Motor

Front 59

(XII) Hypoglossal
Function:

Back 59

LMN: innervates muscles of tongue

Front 60

(XII) Hypoglossal
Clinical Exam:

Back 60

Tongue movements,
Tremor,
Wasting or wrinkling of tongue

Front 61

(XII) Hypoglossal
Typical Dysfunction:

Back 61

Ipsilateral LMN paralysis of the tongue
Wasting of tongue with deviation to side of lesion on protrusion