Anatomy - Cranial Nerves Flashcards Preview

Block 3 - Resp > Anatomy - Cranial Nerves > Flashcards

Flashcards in Anatomy - Cranial Nerves Deck (54):
1

Three nerves for the eye

- Oculomotor (III)
- Trochlear (IV)
- Abducent (VI)

2

Oculomotor nerve course

- from brainstem, in between the two pillars
- lies upon circle of willins
- to cavernous sinus (on lateral wall)
- through superior orbital fissure
- gives off motor nerves
- parasympathetic goes through ciliary ganglion

3

Through which foramina does the oculomotor nerve exit?

Superior orbital fissure

4

What ganglion does the parasympathetic part of oculomotor go through

Ciliary Ganglion

5

What does the parasympathetic fibers of the oculomotor nerve innervate

- Ciliaris
- sphincter pupillae

6

What do the motor fibers of the oculomotor nerve innervate

- Most muscles of the eye except SO and LR

- LPS
- MR
- SR
- IO
- IR

7

Clinical issues with the oculomotor nerve

- hemmorage near circle of willis, aneurysms

- pupil dilation: mydriasis
- no pupillary reflex
- no accomodation
- lateral squint: down-out
- diplopia: double vision
- ptosis: because LPS is damaged

8

Trochlear nerve course

- only cranial nerve that crosses to the other side in the periphery
- goes through cavernous sinus on lateral wall
- exits skull through the orbital fissure
- along the superior eyelid

9

What type of fibers does the trochlear nerve have

- only motor

10

What fissure does the trochlear nerve exit by

- Superior orbital fissure

11

What does the trochlear nerve innervate

- Superior oblique

12

Clinical issues for the trochlear nerve

- rise in intracranial pressure

- slight lateral squint (extortio) - patients may try to correct this by tilting their head to one side. This is because the inferio oblique is rising the eye and SO cant contradict it
- weak eye depression when adducted
- diplopia

13

Abducent nerve course (VI)

- stupid
- down then hits sphenoid bone, goes back up
- goes through cavernous sinus next to internal carotid
- exits via superior orbital fissure
- innervates lateral rectus

14

What fissure does the abducent nerve use to exit the skull?

- the superior orbital fissure

15

What does the motor fibers of abducent nerve innervate?

- lateral rectus

16

What type of fibers does the abducent nerve have?

- motor only

17

Clinical issues with abducent nerve

- carotid dilation, pathology, rICP
- medial squint: esotropia: diplopia

18

Two cranial nerves for the face area

- Trigeminal (V)
- Facial (VII)

19

Trigeminal nerve three parts

- ophtalmic: V1
- Maxillary: V2
- Mandibular: V3

V1 and V2 are purely snesory
V3 is sensory but has a motor component

20

Trigeminal nerve course

- where does the trigeminal nerve exit?
- where does it form a swelling
- Where does V1 go through?
- Where does V2 go through?
- where does V3 go through?

- Exit midbrain through Merkel's cave
- forms a swelling over the petrous temporal bone and then fibers separate
- V1 through superior orbital fissure
- V2 through foramen rotundum
- V3 through foramen ovale

21

What is the sensory innervztion of V1

- scalp
- forehead
- sinus
- eyelids
- nose
- nasal cavity
- eye

- HEAD BLOOD VESSELS
- MENINGES (particularly dura)

22

What is the sensory innervation of V2

- upper teeth
- palate, sinus
- cheek
- upper lip
- nose
- nasal cavity
- oral cavity
- pharynx

23

What is the sensory innervation of V3

- Lower teeth,
- tongue
- lower lip
- chin
- jaw
- ear

24

What is the motor innervation of V3

- Mastication muscles

- TVP
- Tensor tympanic
- mylohyoid
- ant digastric

25

Clinical issues of trigeminal

- sensory face loss: neuralgia, shingles
- mastication issues: jaw deviation
- headaches: artery dilation/pathology, visceral issues, rICP

26

Facial nerve course

- where does it exit?
- where does the ganglion form
- what structures does it pass

- exits via internal acoustic meatus
- forms a swelling at facial sensory gnaglion and then first division
- second division after tympanic cavity

27

First division of facial nerve:4 courses

1) parasympathetic fiber goes above petrous temporal bone, through trigeminal ganglion. Synapse into pterygopalatine ganglion and post-ganglionic fiber go to lacrimal gland
2) motor fiber to stapediues
3) sensory fibers to ear, auricle
4) some parasympathetic and motor fibers continue

28

Second division of facial nerve

- what fissures do motor fibers and parasympathetic fibers go through?
- what is the ganglion that the parasympathetic fibers synapse to, and where do post-ganglion neurons go to?

- after the first division: goes through tympanic cavity and then further divide
- Motor fibers continue down over mastoid process through stylomastoid foramen and parotid gland
- parasympathetic fiber go through petrotympanic fissure and take advantage of chorda tympani (lingual nerves to send fibers to V3 lingual) - synapse into submandinbular ganglion and post ganglionic fibers innervate submandibular gland and sublingual gland. This is also the path for taste nerves that go to anterior 2/3 of tongue

29

What do the fibers of facial nerve innervate?
- parasympathetic
- sensory
- taste
- motor

- Parasympathetic: lacrimal gland, submandibular/sublingual gland
- Sensory: ear
- Taste: anterior 2/3 of tonghe

- motor: muscles of facial expression + stapedius, stylohyoid, post digastric

30

Clinical issues with facial nerve

- intracranial: sensory/visceral issues ( + hyperacusis), Motor (bell's palsy): middle ear infection/shingles

- extracranial: motor (Bell's palsy): Parotid tumour/infections/ mastoid trauma

31

NErve that innervates ear

- Vestibulo cochlear

32

Cochlear nerve: function

- Sensory: hearing, frequency maps

33

Cochlear nerve: Clinical issues

- abscess/tymour, internal acoustic meatus, inner ear damage

- hearing loss: Rinne and Weber test to distinguish between sensorineural and conductive

- tinnitus

34

What foramina does the vestibulocochlear nerve use to exist brainstem?

- internal acoustic meatus

35

VEstibular nerve function

- sensory

- balance
- posture: position, movement
- ocular (head eye together, stable retinal moves)

36

Clinical issues with vestibular nerve

- Posture: balance loss, unsteady (without eyes)
- ocular: no eye-head moves, nystagmus
- visceral issues: vertigo, vomit, nausea


- will always fall towards sign of lesion

37

Innervation of mouth 3 nerves

- glossopharyngeal
- vagus
- hypoglossal

38

Glossopharyngeal nerve (IX) course

- foramen to leave brainstem
- swelling
- 5 branches off

- leave brainstem through jugular foramen
- swelling at glossopharyngeal sensory ganglion
- 1st branch off: parasympathetic fiber to parotid gland and sensory fiber to middle ear
- 2nd branch off: sensory fiber to carotid body
- 3rd branch off: motor nerve to stylopharyngeus
- 4th branch off: sensory and taste to posterior 1/3 of tongue
- 5th branch: sensory to oropharynx

39

Parasympathetic fibers of glossopharyngeal

- above which bone?
- synapse to which ganglion?
- what do postganglionic fibers innervate

- go above petrous temporal bone
- synapse into otic ganglion
- post ganglionic fiber go to parotid gland

40

Sensory fibers of glossopharyngeal nerve

- oropharynx
- posterior 1/3 of tongue
- carotid body

41

Taste fibers of glossopharyngeal nerve

- posterior 1/3 of tongue

42

- Motor fibers of glossopharyngeal

- stylopharyngeus

43

CLinical issues of glossopharyngeal

- sensory-visceral issues
- no gag reflex

- rare

44

What foramina does the vagus nerve use to exit midbrain

- jugular foramen

Then form vagus sensory ganglion

45

Divisions of vagus nerve: sensory

- one to aorta/baroreceptors
- two separate fibers to vocal folds (posterior and superior)
- laryngopharynx
- thorax/ upper GIT

46

Taste fibers of vagus

- to larynx

47

- parasynmpathetic fibers of vagus

- go through carotid sheath with IJV and CCA an then synapse into thorax/abdomen ganglia
- post ganglioninc fiber innervate thorax and upper GIT

48

Motor branches of vagus nerve

- pharyngeal plexus (middle constrictor)
- muscles of palate (except TVP)
- muscles of pharync (except stylopharyngeus)
- Cricothyroideus and cricopharyngeus
- all laryngeal muscles except cricothyroideus

49

Clinical issues with vagus nerve

- sensory-visceral issues
- dysphonia: recurrent laryngeal is damaged - cant contract cricothyroideus
- dysphagia: problem swallowing because constrictors are not working
- dyspalatia; problems with palate

50

Hypoglossal nerve: course

- exit midbrain through hypoglossal canal
- crosses carotid around the loop of lingual

51

Hypoglossal nerve: innervation

- only motor: tongue

- hyoglossus
- all glossal muscles except palatoglossus

52

Clinical issues with hypoglossal nerve

- nearly always unilateral

- glossal palsy: ask to stick tongue out: deviation to the right (side of lesion)

53

Accessory nerve: neck nnervation

- what spinal levels
- what foramen
- what muscles

- at spinal cord level C1-6
- exit through jugular foramen
- separates into to innervate SCM and trapexius

54

Accessory nerve clinical issues

- shoulder/head movement
- viral infection?
- difficulty turning to opposite side of lesion and shrugging shoulder

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