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Flashcards in head: cranial nerves Deck (48)
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1

where do these cranial nerves originate? CNI , CN II, CN XI

I- cerebrum
II- diencephalon
XI- spinal cord

2

olfactory nerve: where are the receptors, cell bodies, central processes and synapse ?

Receptors in roof of nasal cavity
Cell bodies in nasal mucosa
Central processes enter cranium via cribriform plate
Synapse in olfactory bulb

3

only CN to enter cerebrum

CN I- olfactory

4

Olfactory tracts project to where?

Olfactory tracts project to ipsilateral & contralateral anterior temporal lobes

5

CN II: Optic “nerves” are ___ order neurons
Extensions of ________

3rd, extensions of diencephalon

6

optic chiasm

Medial (nasal) retinal fibers cross & join lateral (temporal) retinal fibers of contralateral eye
Form optic tracts

7

optic tracts

R carries fibers from R half of each retina=left visual field
L carries fibers from L half of each retina=right visual field

8

where do the optic tracts project?

to thalamus then to occipital lobes

9

oculomotor: CN III - what does it do?

Somatic motor-eye/eyelid movement
Visceral motor-constricts pupil, rounds lens (accommodation)
Efferent limb of light reflex

10

CN III originates from two midbrain nuclei

1. Motor-somatic
2. Accessory/parasympathetic (Edinger-Westphal)-visceral
To ciliary ganglion

11

oculomotor nerve + CN IV + CN VI course

Courses lateral to diaphragm sella, crosses internal carotid
Enters orbit via superior orbital fissure

12

Short ciliary nerves (V1) go where?

to sphincter pupillae & ciliary body

13

what is the largest true cranial nerve?

CN V (trigeminal)

14

trigeminal nerve: made of how many brainstem nuclei? - how many are sensory and how many motor? which are larger? where does it emerge from?

4 brainstem nuclei-3 sensory, 1 motor
sensory (large) & motor (small) roots
pons
*Sensory root has central processes from trigeminal (semilunar) ganglion

15

trigeminal ganglion is ____ to cavernous sinuses

lateral

16

do all trigeminal nerve fibers go through the trigem ganglion?

NO! sensory do, but Motor root fibers bypass ganglion
--> Blend with V3 in foramen ovale

17

three branches of opthalmic V1 and their subdivisions

Lacrimal
Frontal: Supraorbital/supra trochlear
Nasociliary: Long/short ciliary, Infratrochlear

18

afferent limb of sneeze reflex

maxillary V2

19

while V2 has 5 branches, which 2 do we care about? what are their subdivisions?

Zygomatic: Zygomaticofacial, Zygomaticotemporal
Infraorbital: Anterior superior alveolar

20

what are the 4 ganglia in the head? what nerve carries ALL postgang PSNS?

Ciliary
Pterygopalatine
Otic
Submandibular
- Postganglionic parasympathetic from all ganglia carried by CN V branches

21

where does CN VI (abducens) enter to orbit?

comes from posterior cranial fossa
Enters at clivus
- enters orbit via SOF

22

which nerve has the longest intradural course?

CN VI

23

which CN has the longest interosseus course?

CN VII

24

where does the facial nerve enter and exit

enter: IAM (facial canal)
exit: stylomastoid foramen

25

where does the facial nerve take a sharp bend?

at the geniculate ganglion

26

three interosseus branches of CN VII (facial)

Greater petrosal
Nerve to stapedius
Chorda tympani

27

Chorda tympani (of facial nerve) enters infratemporal fossa via ______ _______ to meet with lingual V3

petrotympanic fissure

28

what innervates the stapedius (muscle that stabilizes the stapes)?

Branch to stapedius from facial nerve CN VII

29

Facial nerve CN VII- exits cranium via what? to become what 5 extracranial branches?

stylomastoid foramen
temporal, zygomatic, buccal, marginal mandibular, cervical

30

what do the external branches of facial nerve innervate?

Muscles of facial expression
posterior digastric + stylohyoid
Efferent limb of corneal reflex
Orbicularis oculi