Ear

Question 1

Ear structure (11)

Answer 1

Pinna- cartilage flaps with fold to direct sounds into auditory canal

auditory canal- tube from pinna to tympanic membrane
transmit sound waves from pinna to tympanic membrane
wax to prevent drying out
hair to prevent foreign bodies

Tympanic membrane- thin membrane separating outer and middle ear
sound waves from auditory canal vibrste the tympanic which tranmit the sound wave to the ossicles in middle ear

osscicles- 3 small bones Hammer that connects tympanic membrane to anvil which is middle and then stirrup which is connected to the oval window
transmit soundwave and amplifies it

oval window- membrane connecting middle ear to the inner ear- transmits vibrations and amplifies to cohlea

round window- membrane below oval window to absorb excess pressure from sound waves to prevent echoes

eustachian tube- connects middle ear to throat equalize pressure on both sides of tympanic membrane

Semicircular canals- fluid filled tubes in 3 planes with cristae receptors at base (ampulla) to detect change in speed and direction and send impulse to cerebellum

Vestibule- 2 sacs (utriculae and saculae) with maculae receptors to detect changes in position of head relative to gravity and send impulse to cerebellum

cochlea- upper and lower layer with perilymph and middle layer with organ of corti in endolymph to detect sound stimulus and convert to impulse

auditory nerve

Question 2

Define hearing

Answer 2

process by which sounds waves are directed through the ear and impulses are generated and transmitted to the cerebrum for interpetration.

Question 3

process of hearing (10)

Answer 3

pinna directs the sound waves to the auditory canal

sound waves transmitted through auditory canal and vibrates the tympanic membrane

vibrating tympanic membrane vibrates the ossicles

ossicles( hammer, anvil, stirrup) vibrate and amplify the sound waves

oval window further vibrates these sounds as it is smaller (increased pressure)

sound waves transmitted to cochlea endolymph

organ of corti stimulated and an impulse is generated

impulse is sent through auditoy nerve to cerebrum for interpretration.

Round window absorbs excess pressure from sound waves to prevent echoes.exit via eustaschian tube

Question 4

Middle ear infection
cause
treatments

Answer 4

excess fluid build up in middle ear

pathogens caused inflamed fluid that cant be drained from the ear

medications and grommets (small tube surgery into tympanic membrane to allow fluid to be drained out)

Question 5

deafness
causes
treatments

Answer 5

partial or complete hearing loss

injury to nerve of head part that helps in hearing impulse
hardening of ossicles

hearing aid to detect amplify and transmit sound

cochlea implant to generate nervous impulse (electrical) in response to vibrations

Question 6

define maintaining balance

Answer 6

process by which receptors in middle ear detect changes in position, speed and direction of head react to changes.

Question 7

balance due to change in position of head relative to gravity

Answer 7

Position of head changes- vestibules have maculae receptors in the sacculae and utriculae

maculua receptors stimulated as the change in pull of gravity stimulates the hair follicle

macullae receptor sends impulse from vestibule of the cerebellum

cerebellum sends impulse to skeletal muscles to restore balance

Question 8

Balance due to change in speed or direction?

Answer 8

change in speed and direction of head

semicircular canal has 3 tubes in 3 different planes with cristae receptors at the base of each (ampullae)

when direction or speed changes at least one plane will be changed resulting in the stimulation of the cristea receptors (movement of endolymph)

cristea receptors generate impulse and transmit to the cerebellum

cerebellum send impulse to skeletal muscle to restore balance