Anatomy of ear

Question 1

What is the name for the ear on the outside of head?

Answer 1

Auricle

Question 2

What and where is earwax produced?

Answer 2

Sebaceous and ceruminous glands in external acoustic meatus

Question 3

Which nerve passes through the middle ear?

Answer 3

CN VII - facial

Chorda tympani branch of nerve

Question 4

What is the name of the tube that links the middle ear to the nasopharynx?

Where does this tube enter the nasopharynx?

What is the purpose of this tube?

Answer 4

Eustachian tube

Inferior to the pharyngeal tonsil

Equalise pressure in ear to nasopharynx

Question 5

What nerve provides the sensory supply to the middle ear?

Link this to referred pain in tonsillitis

Answer 5

CN IX

CN IX supplies the nasopharynx

Question 6

How can the middle ear be accessed surgically?

Answer 6

Through the mastoid antrum/air cells and then through the mastoid aditius (located on posterior wall)

Question 7

What happens to the ear drum if:
- tympanic pressure > atmospheric

• tympanic pressure < atmospheric

Answer 7

Tympanic > atmospheric = tympanic membrane OUT

Tympanic < atmospheric = tympanic membrane IN

(link to AOM when pressure increases in middle ear eardrum bulges out)

(think of as higher pressure literally pushes the eardrum)

Question 8

How is sound conveyed in the middle ear?

Answer 8

Through bone conduction

The ossicles get smaller = amplification

Question 9

What bone is most present on inspection of the tympanic membrane?

Answer 9

Malleus

Question 10

What is the name of the hole that leads from the middle ear into the atrium of the mastoid bone?

Answer 10

Aditus