Ear

Question 1

What is present inside the external acoustic meatus as a protective barrier against foreign microorganisms?

Answer 1

tiny hairs are present and ceruminous glands secrete cerumin (wax)

Question 2

At what angle does the tympanic membrane (ear drum) sit to the external acoustic meatus?

Answer 2

45 degrees

Question 3

What instrument can be used to inspect the tympanic membrane? What is the risks of using this in children?

Answer 3

an auriscope
pinna should be pulled upwards and outwards to straighten canal
tympanic ring of bone is present in children which grows laterally into plate

Question 4

What are the name of the three ossicles of the middle ear? Which one of these can be seen on the tympanic membrane?

Answer 4

Malleus - handle of this can be seen on tympanic membrane
Incus
Stapes

Question 5

What is the importance of the auditory tube?

Answer 5

It takes ‘new’ air from the nasopharynx into the middle ear cavity

Question 6

What is the name of the oval window which connects the middle ear cavity to the inner ear? Which ossicle contacts this directly?

Answer 6

fenestra vestibuli

stapes

Question 7

What is the name of the round window which connects the middle ear to the inner ear? What is its importance?

Answer 7

fenestra cochlae

contains membrane which vibrates out when stapes moves into oval window - allows movement of fluid in cochlea

Question 8

Which muscle attaches to the handle of the malleus? What is its importance? Which CN supplies this?

Answer 8

tensor tympani m.
contracts to dampen large movements of ossicles during loud noises
supplies by CNV

Question 9

Which muscle attaches to the stapes and its function is to contract to dampen large movements during loud noises?

Answer 9

Stapedius

Question 10

What is the function of the pinna (auricle)?

Answer 10

Acts as a funnel/trumpet to channel and amplify sound into the passageway of the external acoustic meatus