Ear

Question 1

parts of the ear

Answer 1

external, middle and internal

Question 2

middle ear components

Answer 2

malleus, incus, stapes

Question 3

internal ear components

Answer 3

cochlea and semicircular canals

Question 4

what nerves can be found inn the external ear

Answer 4

CN’s 5,7,9,10

Question 5

purpose of the auricle

Answer 5

funnels sound into the ear from surroundings but also reduces input from the posterior aspect

Question 6

external ear/ear wax function

Answer 6

composed mostly of soft tissue= allows hair and ear wax to form
ear wax works as a protective barrier to increase water resistance in the ear, anti-bug, and works to remove dead skin from the interior as well

Question 7

what seperates the external ear from the middle ear

Answer 7

tympanic membrane

Question 8

the eustachian tube connects to which part of the ear?

Answer 8

middle ear

Question 9

which ear structure is used for hearing

Answer 9

cochlea

Question 10

which strucutre is used for balance

Answer 10

semicircular canals

Question 11

function of the middle ear, how sound effects it?

Answer 11

sound moves into the ear as sound waves that push on the tympanic membrane that then presses on the malleus which presses on the incus and eventually the stapes which presses on the oval window. pressure on the oval window causes a fluid distortion that is converted to nn activity

Question 12

how is the sound amplified

Answer 12

tympanic membrane is larger that the oval window which results in sound amplification
malleus, incus and stapes also form a lever action which helps to amplify hearing as well.

Question 13

skin of the internal aspect of the external ear, implication?

Answer 13

directly on bone without underlying tisse=very weak

can be ruptured which leads to bacterial infection (lots of bacteria in the ear)

Question 14

portions of the tympanic membrane, significance?

Answer 14

Pars tensa: 3 layers, rigid
pars flacida; 2 layer, less stiff
With ET dysfunction- pressure can cause the pars flacida to be pulled in as its less stiff

Question 15

what nn passes thru the middle ear

Answer 15

chorda tympani

Question 16

temporary tubes for ear infections

Answer 16

done in cases of chronic infection or ET dysfunction
slice the typmanic membrane and place a tube that allows the mid ear to connect with the outside world
can also allow the direct administering of drops of antibiotics for severe ear infections

Question 17

fluids of the internal ear

Answer 17

endolymph- within the labyrinth, similar to ICF

perilymph- outside the labyrinth, similar to ECF

Question 18

fracture of the temporal bone effects on the fluids of the internal ear

Answer 18

can lead to their mixture is severe which can result in a loss of hearing/ balance

Question 19

semicircular canals

Answer 19

responsible for the detection of our position in 3 planes

Due to the 3 canals being positioned in 3 different planes

Question 20

hearing mechanism at the cochlea

Answer 20

basement membrane is moved with distortion due to perilymph movement
which causes hair cells to be moved into the tectorial membrane resulting in neuronal stimulation of the cochlear nerve (in direction towards kinocilia)

Question 21

hair cells responsible for hearing, others?

Answer 21

95% hearing from inner hair cells

outer hair cells may contribute to fine-tuning of hearing

Question 22

utricle and saccule significance

Answer 22

both possess muculae-hair cells capable of detecting changes to acceleration and gravity

Question 23

vestibular ganglion

Answer 23

portion of the vestibulocochlear nn that receives information from the maculae and semicircular canals

Question 24

oreinatation of the head mechanism

Answer 24

tilting of the head will move the gelatinous layer above the hair cells and cause their distortion which stimulates them
leads to perception of head position

Question 25

how we can percieve dif sound frequencies

Answer 25

high and low frequency sounds move variable distance into the cochlear tubing, high freq is short distance and long is further, this will activate dif hair cells to perceive the different stimuli

Question 26

round window

Answer 26

acts as a vent to allow waves out of the internal ear and back to the middle ear which prevents echo

Question 27

organ of corti

Answer 27

where mechanical info is translated into neurological info
possess the inner and outer hair cells
hair cells with streocilla- deformation towards the kinocilia (larger ones) results in depolarization, whereas deformation away from these cause inhibition

Question 28

loud sounds effects on hair cells

Answer 28

damaging, can be temporary or permanent

Question 29

cochlear implants

Answer 29

microphone projects sound to external coil which project signal to internal coil that then projects wire to the active electrode of the cochlea to send electrical signals to the cochlear nn