auditory path and common eye conditions

Question 1

describe the outer and middle ear and most common pathologies

Answer 1

outer ear: includes auditory canal and eardru. transfers sound waves via vibration of the eardrum
middle ear is an air-filled space w/ 3 ossicle bones: stapes, malleus, and incus. they conduct and amplify sound from the inner ear

Question 2

Where are different frequencies best conducted in the inner ear?

Answer 2

on the basilar membrane. low freq hear at the apex near the helicotrema (end); high freq heard best at the base (thin and rigid)

Question 3

How does noise-induced hearing loss work?

Answer 3

damage to sterocilliated cells in organ of corti; loss of high-freq hearing first. sudden extremely loud noises can produce hearing loss d/t typmanic membrane rupture

Question 4

What are some causes of facial nerve palsy?

Answer 4

may be idiopathic, but is also associated with Lyme disease, HSV and (less commonly, HZV), sarcoidosis, tumors and DM

Question 5

What muscle(s) close the jaw? What is the innervation?

Answer 5

Masseter, temporalis, and medial pterygoid

innervated by V3

Question 6

What muscle(s) open the jaw? What is the innervation?

Answer 6

lateral pterygoid

Innervated by V3

Question 7

Draw and eye. include chambers, layers of the wall (3 layers), areas where light hit, chambers. Include ciliary body cornea, sclera, lens, iris, pupil,zonular fibers, canal of schlemm

Answer 7

see pg 476

Question 8

hyperopia vs. mypoia. include the problem btw the focusing lens/cornea

Answer 8

hyperopia: far-sighted. eyes are too short for the refractive power of the lens, so light focuses behind the retina
myopia: near-sighted. eye is too long for the cornea and the lens, so the light focuses in front of the retina.

Question 9

What is astigmatism? What is the anatomical structure that causes this problem?

Answer 9

abnormal curvature of the cornea leading to different refractive power at different axes

Question 10

What is presbyopia?

Answer 10

decrease in focusing ability during accomodation d/t sclerosis and decr. elasticity.

Question 11

What is the uvea, and what is uveitis?

Answer 11

The uvea refers to the middle layer of the eye, including the choroid, iris, and ciliary body. In uveitis, there is inflammation of the anterior uvea/iris, plus steril pus and conjunctival redness

Question 12

What are some conditions associated with uveitis?

Answer 12

systemic inflammation: sarcoid, RA, juvenile idiopathic arthritis, TB, HLA-B27 associated conditions (PAIR: psoriatic arthritis, ankolysing spondylitis, IBD, reactive arthritis)

Question 13

What is retinitis? Causes? Associations?

Answer 13

retinal edema and necrosis that leads to a scar. often viral (CMV, HSV, HZV). associated with immuno suppression

Question 14

What is central retinal artery occlusion?

Answer 14

acute, painless monocular vision loss. retina is cloudy with attenuated vessels and “cherry-red spots” at the fovea

Question 15

What is the cause of retinal vein occlusion?

Answer 15

compression from nearby arterial atherosclerosis. may cause retinal hemorrhage and edema

Question 16

What are the 2 types of diabetic retinopathy? Pathophysiology and treatment?

Answer 16

non-proliferative: damaged capillaries leak blood, causing lipids and fluids to seep into the retina. This causes hemorrhage and macular edema. May treat with macular laser.
Proliferative: chronic hypoxia results in new blood vessel formation with resultant traction on retina. treat with peripheral retinal photocoagulation, anti-VEGF injections.