LEC50: Cranial Nerves I Flashcards Preview

Structures: Part Deux > LEC50: Cranial Nerves I > Flashcards

Flashcards in LEC50: Cranial Nerves I Deck (72):
1

2 types of bone formation of human skull 

1) bottom: cartilagenous endochondral

2) face: membranous

2

which area of the skull is evolutionarily older? 

bottom of skull, the chondrocranial base

3

which area of skull is malleable? which is not? why?

face/vault is malleable 

bottom of skull isn't malleable b/c cranial foramina there, where nerves exit / vascular supply enters 

4

what is fontanella? 

soft spot on top of baby's skull 

newborn's face/vault very malleable; skull base is not malleable

5

what is hydrocephalus 

abnormal accumulation of CSF in brain; increases intracranial pressure inside skull, progressively enlarges head

most common in infants 

6

what view of skull is this 

 

Q image thumb

exocranial view of skull 

7

what view of what structure is this? what does it enable visualization of? 

 

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endocranial view of skull base 

see important foramina

8

list cranial nerves, by number and name

I: olfactory 

II: optic

III: oculomotor

IV: trochlear 

V: trieminal

VI: abducens

VII: facial

VIII: vestibulo-cochlear

IX: glossopharyngeal

X: vagus

XI: spinal accessory

XII: hypoglossal

 

9

"general" nerve fibers defn, types

fibers that can be found anywhere in the body

4 types: 

GSE, general somatic efferent

GVE, general visceral efferent

GSA, general somatic afferent

GVA, general visceral afferent

10

meaning of "general" re: spinal nerves

found anywhere in the body

11

meaning of "somatic/visceral" re: spinal nerves

visceral: gut innervated

somatic: not gut innervated

 

12

meaning of "efferent/afferent" re: spinal nerves 

efferent: motor

afferent: sensory

13

"special" nerve fibers of the head/neck (3)

1) SVE, special visceral efferent

2) SVA, special visceral afferent

3) SSA, special somatic afferent 

14

what are SVE fibers? why visceral?

MOTOR fibers relating to muscles derived from the branchial arches 

VISCERAL designation THOUGH GO TO SKELETAL MUSCLE! because branchial arches at first were part of aero-digestive system 

15

what are SVA fibers?

fibers relating to taste, smell 

16

what are SSA fibers?

non-gut related special sense fibers 

vision, balance, hearing

17

how many types of fibers can a cranial nerve have?

up to 7 because 4 general and 3 special types of fibers

however, max number found is 5! 

18

3 groupings of cranial nerves

1) special sensory nerves 

2) myotomal nerves 

3) branchiomeric nerves 

*3, 4, 5 system of subdividing cranial nerves*

19

special sensory nerves are? 

*3*

I: olfactory

II: optic

VIII: vestibulo-cochlear

20

myotomal nerves are? general fxn? 

III: oculomotor

IV: trochlear

VI: abducens

XII: hypoglossal

innervate skeletal muscle derived from myotomes

*4*

21

branchiomeric nerves are? general fxn? 

V: trigeminal

VII: facial

IX: glossopharyngeal

X: vagus

XI: spinal accessory

nerves related to branchial arches

*5*

22

fiber type, CNI: olfactory nerve

SVA

23

fiber type, CNII: optic nerve

SSA

24

fiber type, CNVIII: vestibulo-cochlear n

SSA

25

what is misnomer about CNI: olfactory n / why? 

not actually a nerve; it's a brain tract

was called nerve historically, so misnomer stuck 

nerve must either: 1) if motor, go from motor nucleus > muscle or 2) if sensory, have a primary sensory neuron in a ganglia - CNI has neither

 

26

structure of CNI: olfactory n?

olfactory tract, bulb, nerve 

 

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27

important structures of this image? 

 

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olfactory bulb, nerve, tract 

specialized sensory epithelium 

communicates w/ mitral tufted cell and nerve

28

hyperosmia

heightened sense of smell 

re: CNI, olfactory nerve 

cocaine users have hyperosmia

29

cacosmia

condition where always perceive foul odors, even if none present

30

what's unique about CNII: optic nerve structure? 

is an optic tract/brain tract, like olfactory nerve- it's NOT A NERVE

 

31

where does CNII: optic nerve run? 

from visual cortex > through optic foramena 

 

A image thumb
32

where is CNI: olfactory n located?

small fibers in nose septum and undearneath in turbiantes lying on superior nasal concha

pass through cribiform plate of ethmoid bone

 

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33

what foramena is this? what goes through it? 

 

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optic foramena

CNII, optic n

34

how does 1-eyed blindness present in brain?

atrophy of optic n

35

is brain sensitive to pain? 

no, dura surrounding brain is

36

astrocytoma?

tumor in brain - swelling in brain tissue 

37

where do you find optic astrocytoma?

near chiasm

38

function of CNVIII

CNVIII: vestibulocochlear nerve 

hearing, balance

39

where does CNVIII: vestibulo-cochlear nerve exit skull base

internal acoustic meatus

40

fiber type of nerves i nmyotomal nerve group? 

all are GSE EXCEPT CNIII, oculomoter, also GVE parasympathetic fibers

41

nerves of oculomotor system, function

CNIII, oculomotor; IV, trochlear; VI, abducens

move the eyeball

42

which cranial nerves are innervating this structure 

 

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III, IV, VI

43

what is this condition? what cranial nerve's affected?

 

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congenital bilateral external rectus palsy 

CNVI: abducens palsy

44

what is major nerve for tongue innervation?

hypoglossal n

45

what nerve fiber type do all branchiomeric group nerves have? 

SVE, because derived from branchial arches 

46

nerve fiber types for CNV, trigeminal n

SVE, GSA

47

nerve fiber types for CNVII, facial n

SVE: branchial mm - 2nd arch

GSA: general somatic sensation

GVE: parasympathetic fibers

SVA: taste, anterior 2/3 tongue 

48

nerve fiber types for CNIX, glossopharyngeal n

SVE: branchial mm, 3rd arch 

GVA: general visceral sensation 

GVE: parasympathetic fibers 

GSA: general somatic sensation 

SVA: taste, posterior 1/3 of tongue

49

nerve fiber types for CNX, vagus 

SVE: branchial mm, 4th arch 

GSA: general somatic sensation 

GVE: parasympathetic fibers 

GSA: general somatic sensation 

SVA: taste, epiglottis 

50

nerve fiber types, CNXI, spinal accessory n

SVE: branchial archs 5-6 

GSE: spinal part

51

what innervates mastication muscles? 

SVE of CNV, trigeminal n

52

CNV, trigeminal n, divisions? 

V1: opthalmic 

V2: maxillary 

V3: mandibular 

53

name nerve, divisions

 

Q image thumb

trigeminal n

green: V1, opthalmic

blue: V2, maxillary 

salmon: V3, mandibular 

A image thumb
54

sensory field of CNV, trigeminal n, both re: divisions and overall

A image thumb
55

cause and presentation of trigeminal neuralgia? possible cause?

compression of 1 division of trigeminal n

unrelenting, intense pain 

possible cause- artery compressing nerve/branches

56

functions of CNVII, facial n? 

facial expression muscles- smile, frown, close eyelids 

carries taste from anterior 2/3 of tongue

57

where does CNVII, facial n, pass through? 

through temporal bone's internal auditory canal 

through parotid gland > facial muscles

58

what is this example of? 

 

Q image thumb

bell's palsy aka facial palsy

CNVII, facial n, insulted 

59

nerve fibers of glossopharyngeal n, CNIX? 

5! most found in any CN (+ vagus also 5) 

SVA: branchial, 3rd arch 

GVA

GVE: parasympathetic

GSA

SVA: taste, posterior 1/3 tongue

60

key nerve for gag reflex? 

CNIX, glossopharyngeal nerve

61

what comes out of jugular foramen?

CNIX- glossopharyngeal, CNX- vagus 

62

what structure carries taste?

epiglottis

63

nerve fibers/their fxns for CNX, vagus?

SVE- branchial, 4th arch

GVA 

GVE 

GSA

SVA- taste, epiglottis

64

where are primary sensory neurons of cranial nerves located? 

in ganglia OUTSIDE the CNS - like DRGs of spinal nerves

65

which cranial nerves do not have ganglia? 

CNI, CNII because not real nerves 

66

sensory ganglia of the cranial nerves? 

CNV: trigeminal (semilunar) ganglion - LARGEST, MOST IMPORTANT

CNVII: geniculate ganglion 

CNVIII: vestibular ganglion; cochlearn (spiral) ganglion 

CNIX: superior and inferior glosspoharyngeal ganglia

CNX: superior (jugular) and ifnerior (nodose) ganglia

67

what is a shockingly sensitive part of the body? 

auricle

68

what provides auricular sensation and to where?

CNV- auriculotemporal branch

CNVII- small area, posterior canal wall

CNIX- medial, inner part of tympanic membrane (tympanic n)

CNX- most of ear canal, pt of outer surface of tympanic membrane (auricular br; arnold's s n) 

Greater auricular n (C2, C3)

Lesser occipital n (C2)

69

nerve fiber types of parts of CNXI, spinal accessory n

SVE- cranial root 

GSE- spinal part

70

what does spinal part of CNXI innervate?

trapezius m- adduct arm, elevate shoulder

sternocleidomastoid m- tilts, rotates head

71

what happens to cranial part of CNXI, spinal accessory n?

joins CNX, vagus n

72

what is spinal accessory nerve's route?

UNIQUE b/c both enters and exits skull: 

arises from C1-C5 ventral horn cells; forms trunk

ascends into skull thru foramen magnum

then exits skull thru jugular foramen, with CNX 

runs backwards, descends obliquely behidn digastric and stylohyoid muscles to upper pt of sternocleidomastoid; courses obliquely across neck, to trapezius m