Auditory Pathway

Question 1

External ears recieve what waves

Answer 1

sound

Question 2

Middle ear receives what waves and turns to what

Answer 2

Sound -> mechanical

Question 3

Inner ear receives what waves and turns to what

Answer 3

Mechanical -> electrical

Question 4

Why is middle ear high risk space

Answer 4

Connected to nasopharynx
Connected to mastoid air cells
Connected to IJV
Connected to IC artery
Traversed by chorda tympani and facial canal

Question 5

two parts of temporal bone

Answer 5

petrous bone - hardest bone of entire body

squamous bone - flat

Question 6

inner acoustic meatus has what through it

Answer 6

vestibulocochlear nerve

facial nerve

Question 7

where does vestibulocochlear nerve terminate

Answer 7

in the petrous part of the temporal

the facial continues on and gives off some branches….

Question 8

where does the chorda tympani go?

Answer 8

to the tongue

Question 9

order of small bone hits

Answer 9

malleus to incus to stapes

Question 10

electrolyte make up of perilymph

Answer 10

high in sodium
low in potassium
mainly made of ECF
allows formation of electrical potentials

Question 11

what is the cochlear duct?

Answer 11

'a water balloon'
membranous sac full of endolymph 
low in sodium
high in potassium
more like intracellular fluid

Question 12

name of two chambers in cochlear duct

which is distal

Answer 12

scala vestibuli
scala tympani
vestibuli is on top

Question 13

which window does energy waves go through and excess water go out?

Answer 13

in through oval

out through round

Question 14

so which lymph effects which lymph

Answer 14

perilymph distorts the endolymph in the cochlear duct

Question 15

roof of the cochlear

Answer 15

vestibular membrane

Question 16

base of the cochlear

Answer 16

basement/basilar membrane

Question 17

which layer has hair cells

Answer 17

basement/basilar

Question 18

what causes an influx of ions?

Answer 18

the cilia produce sheering forces which open ions channels which causes an influx of ions

Question 19

where are first order fibres contained

Answer 19

spiral ganglion - bipolar neuron

Question 20

what do the first order fibres go on to form

Answer 20

cochlear nerve which becomes part of vestibulocochlear

Question 21

where do the first order fibres enter the brain stem

Answer 21

cerebellopontine angle

Question 22

where do first order synapse with second order neuron

Answer 22

dorsal and ventral cochlear nuclei

Question 23

where does vestibulocochlear go to

Answer 23

cochlear nuclei

Question 24

cochlear nuclei go where

Answer 24

superior olivary nucleus

Question 25

superior olivary nuclei go where

Answer 25

inferior colliculus

Question 26

inferior colliculus go where

Answer 26

medial geniculate nucleus of the thalamus

Question 27

medial geniculate fibres go where

Answer 27

the temporal lobe

Question 28

where so many auditory centres?

Answer 28

Polysynaptic and bilateral

Question 29

what is bilateral in respect to hearing and how does it work

Answer 29

hearing on both sides so sound can be localised does this via comparing timing and loudness

Question 30

from cochlear nuclei, how is the information distributed

Answer 30

to superior olivary nucleus via trapezoid body and slightly more goes to the right hand side

Question 31

what happens to information in the inf. colliculus

Answer 31

communication between both sides

Question 32

where and what is the primary auditory cortex

Answer 32

heschl's gyrus deep in the sup. temporal lobe

Question 33

how does pitch work in the basilar membrane

Answer 33

apex responds to low pitch and sends this information to anterolateral part of heschl's gyrus

Question 34

broca's area

Answer 34

anterior - motor/production of words

Question 35

wernicke's area

Answer 35

posterior - sensory/understanding

Question 36

secondary auditory areas

Answer 36

broca's and wernicke's

Question 37

which artery feeds broca's and wernicke's

Answer 37

middle cerebellar artery

Question 38

descending fibres pathways for auditory

Answer 38

from cochlear nuclei -> cochlear giving feedback sup. olivary to stapedius and tensor tympani inf. colliculus causes reflex head and eye movement

Question 39

Superior olivary nucleus sends motor fibres to what via what Why

Answer 39

To stapedius via CNVII To tensor tympani via CNV3 Prevents damage during loud noise

Question 40

Inf. colliculus sends motor fibres to what via what Why

Answer 40

Reflex head and eye movements CNIII, VI