Cranial nerves 6 Flashcards Preview

MD4001 Anatomy > Cranial nerves 6 > Flashcards

Flashcards in Cranial nerves 6 Deck (38)
1

where is the olfactory tract and bulb found

on the inferior surface of the frontal lobe

2

where does cranial nerve 8 emerge

with cn7 between the cerebellum and the pons

3

where do olfactory nerves arise from

the olfactory bulb and pass through the cribriform plate of the ethmoid to the upper aspect of the nasal cavity

4

what structures pass through the optic foramen

optic nerve, opthalmic branch of the internal carotid to the orbit

5

what structures lie in the internal accoustic meatus

vestibulocochlear nerve, facial nerve and labyrinthine artery (from basilar)

passes from inside the skull to structures of the inner ear

6

what can cause narrowing of the internal accoustic meatus

acoustic neuroma (most common)
mastoiditis
Paget's disease

7

where do cn 7 and 8 go after emerging from the internal accoustic meatus

pierce the dura to run in the subarachnoid space to reach the medulla in the angle between the cerebellum and the pons

8

where is the internal accoustic meatus

petrous part of the temporal bone of the skull between the posterior cranial fossa and the inner ear
close to the foramen magnum

9

where is the external accoustic meatus

posterior to the condylar process, superior to the styloid process and anterior to the mastoid process

10

what is the effect of tumours in the internal accoustic meatus and cerebello pontine angle

impingement on cn 7 and 8 giving ipsilateral facial signs

11

what is the choroid plexus

a group of cells that produces CSF in the ventricles

ependymal cells

one in each ventricle

12

what structures make up the external ear

auricle, external accousic meatus

13

what structures make up the middle ear

ossicles, tympanic membrane
connection to pharynx via eustacian/auditory/ pharyngotympanic tube

14

what structures make up the inner ear

semi circular canals,
cochlear

15

what structure passes through the stylomastoid foramen

facial

16

what are the three semicircular canals called

anterior, lateral and posterior, at right angles

17

where can the vestibulocochlear apparatus be found on the petrous bone

middle cranial fossa, petrous temporal bone, on a slight elevation on the bone surface caused by the anterior semicircular canal

18

what is the tympanic plate

part of the temporal bone in front of the mastoid process, surrounds the external part of the ear canal
forms the anterior wall, floor and part of the posterior wall of the bony ear canal

19

what is the function of the cochlear and vestibular aqueducts

allows the membranous labyrintheto connect with the subarachnoid space
for reabsorption of peri and endolymph

20

what is the function of the auricle

catch and funnel sound into the EAM

21

name the main parts of the auricle

helix, antihelix, concha, tragus, antitragus, lobule

22

what nerve supplies muscles that can move the position of the auricle

cn 7, facial

23

how long is the EAM

2.5cm

24

what tissue makes up the lateral third of the EAM

cartilage

25

what tissue makes up the medial third of the EAM

bone

26

what tissues line the EAM

skin, hairs, ceruminous glands that secrete ear wax

27

how can the EAM be straightened to facilitate examination of the tympanic membrane

by
pulling the ear
superiorly,
posteriorly and
slightly laterally

28

what is the sensory supply to the auricle

greater auricular nerve (C2 and 3)

facial nerve

lesser occipital (c2 and 3)

auriculotemporal nerve (cnV3)

29

what is the sensory supply of the EAM

auricular branch of vagus

auriculotemporal branch of V3

30

what is the sensory supply to the tympanic membrane and the middle ear

glossopharyngeal 9

31

how is the tympanic membrane held within the temporal bone

by a fibrocartilaginous ring

lies facing downwars and anteriorly

32

what tissues make up the tympanic membrane

skin, facia, mucous membrane

cn9

33

what is the umbo

a rounded protruberance on the tympanic membrane caused by attachment of the tip of the malleus

34

what is the function of the round window

pressure release from the cochlear

35

where is sound tranmitted to after the ossicles

oval window of the cochlear which converts the mechanical impulses to electrical signals

36

which ossicle is in contact with the oval window

stapes

37

in what order do the ossicles lie in

malleus, incus, stapes

38

what is hyperacusis

intolerance to everyday sounds that causes distress