Ch. 14: Cranial Nerves Flashcards Preview

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Flashcards in Ch. 14: Cranial Nerves Deck (44):
1

cranial nerves involved in speaking

V, VII, X, XII

-X (larynx, soft palate)
-VII (lips)
-V (Jaw)
-XII (tongue)

2

Stages of Swallowing

-Oral (V, VII, XII)
-Laryngeal/Pharyngeal (IX, X)
-Esophageal (X)

3

CN X dysfunction

-hard to speak
-hoarse voice
-asymmetric elevation of soft palate
-loss efferent gag
-loss efferent swallow
-poor digestion

4

CN I Function

-Olfactory
-Sensory=smell

(olfactory nerves and olfactory tract)

5

CN II Function

-Optic
-Sensory=vision

conscious vision/reflex (orient head--sup colliculi)

6

3 Functions of CN

-motor innervation
-somatosensory and special sensory innervation
-parasympathetic innervation

7

CN I Dysfunction

-unable to smell
-linked with parkinson's and alzheimers (neurodegeneration)

8

CN II Dysfunction

-blindness
-loss of visual field

-Disrupted pupillary light reflex

9

CN IV function

-Trochlear
-(midbrain)
-move eye medially and down toward tip of nose

10

Medial Longitudinal Fissure

-interconnects CN III, IV, VI, vestiular nuclei and CN XI in brainstem
-wiring bundle connect eye CN to each side to allow conjugate eye movement

11

3 Eye Reflexes

-Pupillary Light Reflex
-Consensual Light Reflex
-Accommodation Reflex

12

CN VI Function

-Abducens
-(border of pons/medulla)
-move eye toward ipsilateral ear

13

Parasympathetic Innervation to pupil and lens

-CN III
-innervates pupillary sphincter and ciliary Mm
-constricts pupil for (near vision)
-increases curvature of lens (for near vision)

14

Pupillary Light Reflex

-unconscious
-Stimulus: light in one eye (CN II)
-Response: constrict pupil (CN III)

15

Consensual Light Reflex

-reflex only
-Stimulus: light in one eye (CN II)
-Response: constriction of both pupils (CN III)

16

CN III Function

-occulomotor
-(Midbrain)
-sup rectus, med rectus, inf rectus, inf oblique

-move eye up, down and adduction

17

Ptosis

-eyelid droops
-(sign of Horner's Syndrome)
-CN III dysfunction

18

Accommodation Reflex

-Consciously driven by visual cortex
-Input: object close to face
-Response: pupils constrict, eyes converge, lens more convex

(opposite with object far from face)

19

CN III dysfunction

-Ptosis
-affected eye looks down and out
-diplopia
-can't move eye med, up or down
-dilation of pupil
-decreased pupillary light reflex
-decreased consensual light reflex
-decreased constriction of pupil for near objects

20

CN IV Dysfunction

-can't look down and inward
-Extorsion due to unopposed action of inf oblique
-(can result in tilted head to compensate for rotated eye)

21

CN VI Dysfunction

-can't abd eye
-resting position of eye drifts medially

22

Efferent CN V

-Mm of mastication
-muscles that move jaw

23

Medial Longitudinal Fasciculus Dysfunction

-no conjugate eye movement
-CN still work but signal from one side doesn't reach other

24

Jaw Jerk Reflex

Stim: quick stretch to mastication Mm
Response: jaw Mm try to close mouth

25

Trigeminal Neuralgia

-trigeminal nerve pain
-allodynia/hyperalgesia

26

Afferent CN V

-light touch, conscious proprioception, fast/slow pain
-all enter brainstem and cross midline then go to contralat parietal lobe

27

CN V blink reflex

Stim: touch eye (CN V)
Response: blink/close eye (CN VII)

28

CN V Dysfunction

-decreased touch, pain, temp of face
-decreased blink and jaw jerk reflex
-trigeminal neuralgia
-decreased chewing/talking

29

CN VIII Dysfunction

-dizziness/disequilibrium
-hearing loss (conductive, sensorineural)
-decreased location of sounds

30

Sensorineural Hearing Loss

-damage to receptor cells/cochlear nerve
-Peripheral N (VIII): acoustic neroma, tinnitus, hearing loss (LMN)
-Cochlear Nuclei/central pathway: damage to brainstem/brain (UMN)

31

CN VII Dysfunction

-paralysis/paresis of facial expression Mm on ipsilateral face
-bell's palsy: LMN damage to CN VII
-can't produce tears

32

Conductive hearing Loss

-impairment of converting air waves to water waves
-extensive wax/otitis media (inflamed middle ear)

33

CN IV Dysfunction

-decreased afferent gag reflex
-decreased afferent swallow reflex
-decreased salivation

34

CN IX Function

-Glossopharyngeal N
-(sensory, motor, autonomic)
-Sensory: back of tongue, soft palate, pharynx, taste (bitter)
-sensory part of gag reflex
-Autonomic: salivary

35

CN XI Dysfunction

-LMN: "flaccid" paralysis of ipsilateral upper trap and SCM
-UMN: "spastic" paresis of contralaterals upper trap and SCM

36

CN XI Function

-spinal accessory nerve
-(Motor)
-Trap/SCM Mm

37

CN XII Function

-hypoglossal
-(motor)
-intrinsic and extrinsic tongue Mm

38

CN XII Dysfunction

-atrophy ipsilateral tongue
-tongue drift to side of lesion
-difficult to speak/swallow

39

CN VII Function

-Motor: facial expression muscles
-Parasymp: salivary, nasal and lacrimal glands
-Sensory: taste, ant 2/3 tongue

40

CN VIII Function

-Vestibulocochlear N
-(sensory)
-frequency coding
-different air cell area for each frequency
-Sound goes to 3 places (inf colliculus, reticular fomation, auditory cortex)

41

3 Places Sound Signals Go

-Inf Colliculus: localize sound
-Reticular formation: increase arousal in CNS
-Auditory cortex: conscious recognition of sound

42

3 Input Sources to CN LMN

-Corticobulbar tract (LMN)
-Descending Limbic Path (autonomic-->excitability)
-Sensory Input (reflexes)

43

CN V Function

-Trigeminal N
-(motor/sensory)
-Sensory: opthalmic, maxillary, mandibular
-Afferent: sensation face
-Efferent: mastication Mm
-2 reflexes (jaw jerk, blink)

44

CN X Function

-Vagus
-(sens, motor, autonom)
-Sensory: larynx, pharynx, viscera
-Motor: larynx, pharynx, vocal cords
-Autonomic: larynx, pharynx, trachea, lungs, heart, upper GI, pancreas, gall bladder