Ear

Question 1

Middle ear infections ( cause , effect and treatment ) ( 1+5+2)

Answer 1

Cause :
viruses and bacteria (that cause common cold )

Effect :
•middle ear has inflammation
•eustachian tube gets swollen , inflamed and clogged
•therefore pressure on either side ( middle and outer) of ear drum increases ( ear ache)
•Tympanic membrane can’t vibrate freely .•. Hearing loss or bursting of TMP membrane
Treatment :
•medication
•grommets

Question 2

Use of grommets

Answer 2

Help treat middle ear infection by bypassing Eustachian tube and allowing air to continuously enter middle ear

Question 3

Cochlear implants ( for who? What and where and function )

Answer 3

For : people hard at hearing or deaf
What: electrical device / bionic ear
Where : in ear
Function : stimulate functioning auditory nerve inside cochlea with an electric field )

Question 4

Deafness ( causes and treatment ) ( 3+3)

Answer 4

Causes:
• ageing
•injury to parts of ear
•fluid in middle ear

Treatment : 
•medication 
•hearing aids 
•cochlea implants 
•drainage of middle ear

Question 5

Cause in difficulty hearing (3)

Answer 5

* damage to hairs in cochlea 
•diseases 
•injury from noise 
• ageing 
•medicine

Question 6

Function and parts of hearing aids

2+3*2

Answer 6

Function : amplified sound for person hard at hearing by magnifying sound vibrations so surviving hair cells can detect and convert to nerve impulses

Parts :

1) MICROPHONE - RECEIVES sound waves and CONVERTS into electrical impulses
2) AMPLIFIER - RECEIVES electrical impulses from microphone and INCREASES power of signals
3) SPEAKER - RECEIVES amplified sound from amplifier

Question 7

Hearing (7 marks )

Answer 7

1) SOUND WAVES picked up by PINNAE
2) DOWN AUDITORY CANAL
3) TO TYMPANIC MEMBRANE
4) which VIBRATES .•. causes OSSICLES IN MIDDLE EAR to VIBRATE
5) VIBRATIONS are AMPLIFIED - then PASSED to OVAL WINDOW
6) OVAL WINDOW VIBRATES .•. CAUSES PRESSURE WAVES in PERILYMPH of COCHLEA
7) VIBRATIONS PASSED TO ENDOLYMPH
8) And STIMULATE HAIR CELLS IN ORGAN OF CORTI
9) STIMULUS > IMPULSE
10) SENT on AUDITORY NERVE to CEREBRUM

Question 8

Effect of burst eardrum ( 6)

Answer 8

•tympanic membrane would not vibrate freely
• vibrations won’t be passed to ossicles
• .•. No vibrations to oval window
• no pressure waves in perilymph and endolymph
•no stimulation of hair cells in organ of corti
.•. No sound interpreted by cerebrum

Question 9

Missing or fused ossicles ( 5)

Answer 9

• vibrations from tympanic membrane would be passed through air filled middle ear to oval window
•NO AMPLIFICATION
.•. Less pressure waves in perilymph and endolymph
•no stimulation of hair cells in organ of corti
.•. Sound not heard

Question 10

Oval window can’t vibrate (5)

Answer 10

•No pressure waves in perilymph 
.•. none passed to endolymph 
• no stimulation of hair cells in OGC 
.•. No impulse sent on auditory nerve to cerebrum 
.•. No sound interpreted

Question 11

Balance ( where , movement and position )(1+3+3+2)

Answer 11

WHERE : VESTIBULAR APPARATUS *** ( doesn’t involve rest of ear )

MOVEMENT OF HEAD : SEMI*O*CANALS 
•head moves and changes direction of fluid in scc 
•stimulates CRISTAE 
(S>>impulse) 
•impulse sent on auditory nerve 
•to cerebellum to be interpreted 

POSITION OF HEAD : SACCULUS AND UTRICULUS
•position of head changes , fluid in S&U moves
• STIMULATING MACULAE
(S»impulse)
• sent on auditory nerve to cerebellum to be interpreted