A5 Ear

Question 1

Components of external ear

Answer 1

External auditory acoustic meatus

Auricle

Question 2

External auditory meatus

Answer 2

Conducts sound to tympanic membrane

Question 3

Components of the auricle (pinna)

Answer 3

Helix
Anti helix
Concha
Lobule (earlobe)
Tragus

Question 4

How does sound travel?

Answer 4

Sound (vibrations) travel through EAM to tympanic membrane, TM moves, and vibrations are transmitted to the auditory ossicles

Question 5

What are the three bones of the auditory ossicles?

Answer 5

Malleus
Incus
Stapes

Question 6

What is the middle ear connected to?

Answer 6

Middle ear is connected to the nasopharynx via pharyngotympanic tube

Question 7

The pharyngotympanic tube is also known as

Answer 7

Auditory tube aka Eustachian tube

Question 8

The middle ear is protected by which two muscles?

Answer 8

Tensor tympani and stapedius

Question 9

Tensor tympani

Answer 9

Pulls malleus medially and tenses tympanic membrane which reduces the amplitude of oscillations

Question 10

Stapedius

Answer 10

Pulls stapes posteriorly away from the oval window and reduces oscillatory range

Question 11

Describe the pharyngotympanic tube

Answer 11

It connects the tympanic cavity to nasopharynx
There is a bony part and a cartilaginous part
It is lined by a mucous membrane

Question 12

Function of the pharyngotympanic tube

Answer 12

Equalize pressure in the middle ear with atmospheric pressure

Question 13

Are the walls of the tube normally open or closed?

Answer 13

The walls are normally closed and must be actively opened by the muscles of the soft palate

Question 14

What are the muscles of the soft palate?

Answer 14

Levator veli palatini

Tensor veli palatini

Question 15

Otitis media

Answer 15

Middle ear infection

Common in infants and juveniles bc short and less angled PT tube

Question 16

What does the inner ear contain?

Answer 16

Contains vestibulocochlear organ
Petrous part of temporal bone
Semicircular canals
Cochlea

Question 17

Function of vestibulocochlear organ

Answer 17

Functions in sound and balance

Question 18

Semicircular canal function

Answer 18

Specialized areas of sensory organs (maculae) that are sensitive to gravity and linear acceleration via movement in endolymph

Question 19

Innervation of the semicircular canal

Answer 19

Vestibular part of CNVIII

Question 20

Function of cochlea

Answer 20

Hearing

Question 21

Innervation of tensor tympani muscle

Answer 21

CN V3 trigeminal

Question 22

Innervation of the stapedius muscle

Answer 22

CN VII facial, chords tympani

Question 23

Innervation of the PT tube and tympanic membrane

Answer 23

CNIX glossopharyngeal

Question 24

Innervation of the vestibular hair cells and cochlear

Answer 24

CN VIII vestibulocochlear via internal acoustic meatus