Flashcards in auditory path and common eye conditions Deck (16):
describe the outer and middle ear and most common pathologies
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
Where are different frequencies best conducted in the inner ear?
on the basilar membrane. low freq hear at the apex near the helicotrema (end); high freq heard best at the base (thin and rigid)
How does noise-induced hearing loss work?
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
What are some causes of facial nerve palsy?
may be idiopathic, but is also associated with Lyme disease, HSV and (less commonly, HZV), sarcoidosis, tumors and DM
What muscle(s) close the jaw? What is the innervation?
Masseter, temporalis, and medial pterygoid
innervated by V3
What muscle(s) open the jaw? What is the innervation?
Innervated by V3
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
see pg 476
hyperopia vs. mypoia. include the problem btw the focusing lens/cornea
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.
What is astigmatism? What is the anatomical structure that causes this problem?
abnormal curvature of the cornea leading to different refractive power at different axes
What is presbyopia?
decrease in focusing ability during accomodation d/t sclerosis and decr. elasticity.
What is the uvea, and what is uveitis?
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
What are some conditions associated with uveitis?
systemic inflammation: sarcoid, RA, juvenile idiopathic arthritis, TB, HLA-B27 associated conditions (PAIR: psoriatic arthritis, ankolysing spondylitis, IBD, reactive arthritis)
What is retinitis? Causes? Associations?
retinal edema and necrosis that leads to a scar. often viral (CMV, HSV, HZV). associated with immuno suppression
What is central retinal artery occlusion?
acute, painless monocular vision loss. retina is cloudy with attenuated vessels and "cherry-red spots" at the fovea
What is the cause of retinal vein occlusion?
compression from nearby arterial atherosclerosis. may cause retinal hemorrhage and edema