Ear Anatomy

Question 1

Pterion

Answer 1

H-shaped structure

• frontal, parietal, temporal and sphenoid
• thinnest part of skull

Question 2

anterior cranial fossa

Answer 2

frontal, ethmoid, sphenoid

Question 3

middle cranial fossa

Answer 3

sphenoid and tmeporal

Question 4

posterior cranial fossa

Answer 4

tmeporal and occipital

Question 5

External ear

Answer 5

collects and conveys sound waves to tympanic membrane

Question 6

middle ear

Answer 6

amplifies and conducts sound waves to the internal ear

Question 7

internal ear

Answer 7

converts special sensory information into fluid waves, then Action potentials, conducts APs to brain

Question 8

Three parts of Auricle

Answer 8

Helix, Tragus + ear lobe

Question 9

CNV3

Answer 9

superior parts of External acoustic meatus + most of tympanic membrane

Question 10

C2,3

Answer 10

back of auricle and ear lobe

Question 11

CNVII

Answer 11

lateral auricle

Question 12

CNX

Answer 12

Parts of EAM + tympanic membrane

Question 13

External ear skeleton

Answer 13

tmeporal bone + elastic cartilage

Question 14

Produces earwax

Answer 14

ceruminous glands

Question 15

Features of Tympanic Membrane

Answer 15

Pars Flaccida (thin + superior)
Umbo (inward depressed)
Pars Tensa (thick + inferior)

Question 16

Sensory Innervation of tympainc membrane

Answer 16

External = CNV3
Internal = CNIX

Question 17

Ossicles

Answer 17

3 bones of middle ear (articulate via synovial joints):

• Malleus
• Incus
• Stapes

Question 18

Connects middle ear cavity to nasopharynx

Answer 18

Eustachian Tube (sensory from CNIX e.g. tonsilitis referred pain earache)

Question 19

Branch of CNVII and taste buds of anterior 2/3rds of tongue

Answer 19

chorda tympani (connects to CNV3)

Question 20

cochlear =

Answer 20

hearing

Question 21

vestibular =

Answer 21

balance

Question 22

where does the otic capsule sit?

Answer 22

Temporal bone (surrounds the cochlea and semicircular canals)

Question 23

membranous labyrinth sits where?

Answer 23

inside bony labyrinth

Question 24

fluid that fills the bony labyrinth and floats the membranous labyrinth?

Answer 24

perilymph

Question 25

Where does CN VII + VIII connect with the brainstem?

Answer 25

Junction between pons and medulla oblongata

Question 26

Mastoiditis

Answer 26

spread of infection from middle ear cavity