Ear

Question 1

Describe the components of the Outer Ear

Answer 1

Auricle, external accoustic meatus/auditory canal, tympanic membrane

Question 2

Describe the auditory canal

Answer 2

Lateral 1/3rd is cartilage and the medial 2/3rds is bone, there is also hairy skin with cerumen glands to prevent water mixing with skin

Question 3

Describe the function of the tympanic membrane

Answer 3

It transmits vibrations from the EAM to the middle ear

Question 4

Describe the anatomical features of the tympanic membrane

Answer 4

It is concave externally, has a cone of light in the antero-inferior quadrant (will shift in disease) and a handle of malleus

Question 5

WHat are the the non boney features of the middle ear

Answer 5

Epitympanic recess to the mastoid air cells, auditory tube which connects to the nasopharynx, tympanic cavity proper and the Chorda tympani

Question 6

Why are children more prone to Otitis Media

Answer 6

The Auditory canal is more horozontal and therefore predispososes bacteria to access the middle ear

Question 7

What is the chorda tympani

Answer 7

Is a branch of the Facial nerve that has sensory capabilities for taste to the anterior 2/3rds of the tongue. Will exit at the internal acoustic meatus and then run over the tympanic membrane in between the malleus and incus. It will travel with the lingual nerve to the submadibular ganglion. Here will go on to innervate the submandibular and sublingual salivary glands.

Question 8

What are the bones of the middle ear

Answer 8

From lateral to medial they are the malleus, incus and stapes

Question 9

What muscles innervate the bones

Answer 9

Malleus by the Tensor Tympani (CNV2) and the stadedius muscle regulates the stapes

Question 10

Function of the muscle of the inner ear

Answer 10

To prevent transmiting harmful vibrations to the inner ear

Question 11

What is the imprint of the cochlear known as

Answer 11

Promontary

Question 12

What are the features of the Inner ear

Answer 12

Oval window (sound conduction), round window (pressure release), petrous process of temporal bone

Question 13

Difference between endolymph and perilymph

Answer 13

Endo is within the structures of the cochlear and vestibular whereas peri is between the bone and the structures of the cochlear and vestibular

Question 14

What are the componants of the Vestibular system

Answer 14

Semicircular canals (Horozontal, posterior and anterior), ampulla (dynamic equilibrium) and the Utricle and Saccule (static equilibrium)

Question 15

Regions of cochlear

Answer 15

Apex for low frequencies and base for high frequencies

Question 16

Nerve supply for inner ear

Answer 16

CN VIII through the internal auditory meatus