Ear Anatomy

Question 1

Outer visible part of ear is called?

how long?

Answer 1

pinna/auricle

4cm in adults

Question 2

lateral 1/3rd of ear?

Answer 2

skin and cartilage containing ceruminous and sebaceous glands producing wax (cerumen)with thick hairs on outside becoming thinner on the inside providing a protective barrier

Question 3

medial 1/3rd of the ear?

Answer 3

does not have hair or cilia or produce wax

Question 4

Tympanic membrane layers?

Answer 4

1cm with 3 layers:

outer layer is continuous with skin

middle fibrous layer

inner layer of respiratory epithelium

Question 5

what conduct sound waves from TM to inner ear?

Answer 5

ossicles

• stapes
• incus
• malleus

Question 6

what does middle ear connect to? what does it contain?

Answer 6

connects to mastoid system via aditus and nasopharynx via Eustachian tube

contains facial nerve and chorda tympani

Question 7

facial nerve course?

chorda tympani?

Answer 7

travels through temporal bone in the internal acoustic meatus
chorda passes between malleus and incus and out through petrotympanic fissure

Question 8

what does the bony labyrinth consist of?

Answer 8

vestibule
semicircular canals
cochlea

Question 9

membranous labyrinth?

Answer 9

contains fluid (perilymph and endolymph)

Question 10

what is the hearing organ?

Answer 10

cochlea

Question 11

peripheral apparatus to cochlea?

Answer 11

utricle
saccule
semi-circular canals

Question 12

hearing route simplified?

Answer 12

pinna aids to capture sound waves which then travel down the auditory canal which vibrates the TM and goes through the malleus, incus and stapes vibrating the oval window of cochlea which causes pressure waves through fluid and is detected by hair cells in organ of corti then transmitted to brain stem by CN VIII (vestibulocochlear nerve)

Question 13

respiratory epithelium?

Answer 13

ciliated pseudo stratified columnar epithelium