ear lecture

Question 1

What is the path of vibration starting at the stapes?

Answer 1

Vibrations move from the stapes to the oval window to the cochlea as fluid pressure waves and are transmitted into the perilymph of the scala vestibule.
They then travel to the scala tympani and then to the round window which bulges into the middle ear
pressure waves travel from the scala vestibuli to the vestibular membrane to the endolymph of the cochlear duct
the basilar membrane vibrates, which moves the cells of the spiral organ against the tectorial membrane.
the hair cells generate nerve impulses in the cochlear nerve fibers

Question 2

function of the external auditory meatus?

Answer 2

transmits sound to tympanic membrane

Question 3

what are the places the nerve impulses from the vestibular nerve travel to?

Answer 3

vestibular nuclei (pons and medulla oblongata), inferior and cerebellar peduncles to cerebellum

Question 4

function of ceruminous glands?

Answer 4

secrete ear wax

Question 5

what percentage of people over 60 have hearing loss?

Answer 5

25%

Question 6

function of pinna?

Answer 6

captures sound

Question 7

When the stereocilia bend towards the tallest one what happens? What about when it bends the opposite way?

Answer 7

Movement towards the longest stereocilia causes depolarization and excitation. Movement towards the shortest ones causes hyperpolarization and inhibition.

Question 8

what are the parts of the vestibular apparatus

Answer 8

organs that maintain equilibrium

saccule, utricle, and semicircular canals

Question 9

function of tympani tensor

Answer 9

supplied by the mandibular branch of the trigeminal (V) nerve, limits movement and increases tension on the eardrum to prevent damage to the inner ear from loud noises

Question 10

what are the macula receptors for?

Answer 10

static equilibrium

Question 11

Trace the path of sound starting from outside the ear

Answer 11

1. The auricle directs sound waves into the external acoustic meatus.
2. When sound waves strike the tympanic membrane, the alternating waves of high and low pressure in the air cause the tympanic membrane to vibrate back and forth. The tympanic membrane vibrates slowly in response to low-frequency (low-pitched) sounds and rapidly in response to high-frequency (high-pitched) sounds.
3. The central area of the tympanic membrane connects to the malleus, which vibrates along with the tympanic membrane. This vibration is transmitted from the malleus to the incus and then to the stapes.
4. As the stapes moves back and forth, its oval-shaped footplate, which is attached via a ligament to the circumference of the vestibular window, vibrates in the vestibular window. The vibrations at the vestibular window are about 20 times more vigorous than those of the tympanic membrane because the auditory ossicles efficiently transmit small vibrations spread over a large surface area (the tympanic membrane) into larger vibrations at a smaller surface (the vestibular window).
5. The movement of the stapes at the vestibular window sets up fluid pressure waves in the perilymph of the cochlea. As the vestibular window bulges inward, it pushes on the perilymph of the scala vestibuli.
6. Pressure waves are transmitted from the scala vestibuli to the scala tympani and eventually to the cochlear window, causing it to bulge outward into the middle ear. (See 9 in the figure.)
7. As the pressure waves deform the walls of the scala vestibuli and scala tympani, they also push the vestibular membrane back and forth, creating pressure waves in the endolymph inside the cochlear duct.
8. The pressure waves in the endolymph cause the basilar membrane to vibrate, which moves the hair cells of the spiral organ against the tectorial membrane. This leads to bending of the stereocilia and ultimately to the generation of nerve impulses in first-order neurons in cochlear nerve fibers.”

Question 12

what are the semicircular canals responsible for?

Answer 12

dynamic equilibrium

Question 13

the function of the utricle

Answer 13

detects horizontal linear acceleration and deceleration

Question 14

the function of semicircular ducts

Answer 14

Detect rotational acceleration or deceleration

Question 15

What are the parts of the external ear?

Answer 15

pinna, external auditory canal, and tympanic membrane

Question 16

what are otoliths?

Answer 16

calcium carbonate crystals

Question 17

what is the function of the eustachian tube?

Answer 17

regulates air pressure in the middle ear

Question 18

what are the three sections of the ear?

Answer 18

external, middle, inner

Question 19

What is the pathway for the nerve impulses after they leave the ear?

Answer 19

cochlear nerve->medulla oblongata->medial geniculate nucleus of thalamus->primary auditory area of temporal
also go to inferior colliculi

Question 20

function of the saccule

Answer 20

detects vertical linear acceleration or deceleration

Question 21

where is the crista located?

Answer 21

ampula

Question 22

what are the three auditory ossicles and what is their function?

Answer 22

mallus, incus, stapes

transmit and amplify vibrations from the tympanic membrane to the oval window

Question 23

what are the functions of the semicircular canals?

Answer 23

balance and equilibrium with cerebellum

Question 24

Which neurotransmitter is probably released by the bending of the stereocilia?

Answer 24

glutamate

Question 25

define dynamic equilibrium

Answer 25

the maintenance of the body's position in response to sudden movements

Question 26

function of cochlea

Answer 26

Professor said "hearing" is enough but | translates vibrations into neural impulses that the brain can interpret as sound

Question 27

what is loudness determined by?

Answer 27

intensity of sound waves

Question 28

Define static equilibrium

Answer 28

maintenance of the body's position relative to the force of gravity

Question 29

what in has a high concentration in endolymph?

Answer 29

K+

Question 30

which frequency of sounds is registered at the base of the cochlea and which at the top?

Answer 30

high frequency at the base | low frequency at the top