Hearing

Question 1

List the structures of the outer ear.

Answer 1

Pinna (auricle), external auditory canal, tympanic membrane

Question 2

List the structure of the middle ear.

Answer 2

Connected to nasal cavity by Eustachian tube.
Ossicles: Acronym MIS and HAS.
Malleus: Hammer
Incus: Anvil
Stapes: Stirrup. Footplate of stapes rests in the oval
window of cochlea.

Question 3

List the structures of the inner ear

Answer 3

Bony Labyrinth: Filled with perilymph.
Membranous Labyrinth: Filled with endolymph.
Membranous labyrinth consists of cochlea (sound),
utricle & saccule (linear acceleration) and semicircular
canals (rotational acceleration & balance).

Question 4

What are the projection areas and where are they found?

Answer 4

Superior Olive: Localizes sound. Located in brain stem.
Inferior Colliculus: Startle reflex. Also used by both eyes
and ears in the vestibulo-ocular reflex which keeps the
eyes fixed on a single point as the head rotates.