Chp 11 Sensory Organs MedTerms Definitions
Card Set Information
Chp 11 Sensory Organs MedTerms Definitions
angle where the eyes meet
provides stiffness of the eye giving shape
provides protective layering
what are the three layers of the eye?
: white part of the eye; maintains shape, tough fibrous tissue
: middle layer that contains many blood vessels
: sensitive and innermost layer; receives nerve impulses and transmits them to the brain
anterior chamber vs. posterior chamber
: behind the cornea, in front of the iris
: behind the iris, in front of ligaments
ANTERIOR SEGMENT MAKES UP 1/3 OF THE EYE FILLING IT WITH AQUEOUS HUMOR
makes up 2/3 of the eyeball filling it with vitreous humor that contains millions of fibers.
rods vs. cones
: black and white
light sensitive area in the center of the retina
middle pit of macula and contains ONLY CONES, no rods since it has high concentrations of color
"blind spot" NO CONES AND RODS
pigmented layer of the eye
located in chroid layer, set of muscles that adjust thickness of lens to focus.
colorful circular structure that surrounds the pupil; controls amount of light passing through by contracting muscles
focuses light rays entering the eye
black circular opening which permits light to enter the eye
process whereby the eyes make adjustments for seeing objects at various distances
inward movement of the eyes towards each other
normal relationshpi between the refractive POWER for the eye and the SHAPE of the eye that enables light rays to focus correctly on the retina
ability of the lens to bend light rays so they focus on the retina
ability to distinguish object details and shape at distance
drooping of the upper eye lid due to paralysis
nodule or cyst usually on the upper eye lid
eversion of the eyelid; turning it outwards
inversion edge of the eyelid; inward eyelid
"stye" pus filled and painful lesion on the eye
swelling of the tissues surrounding the eye(s)
bleeding between the conjunctiva and the sclera
inflammation of the uvea
scratch to cornea
damage to retina due to complication of DM
condition where the pupils are unequal in size
loss of transparency of the lens that causes a progressive loss of visual clarity
floaters (vitreous floaters)
particles of cellular debris that float in the vitreous humor casting shadows
presence of what appears to be flashes of light
contraction of pupil in response to light, prescription of illegal drugs
dilation of the pupil caused by injury, disease or drugs
involuntary, constant movement of the eyeball.
papilledema (choked disc)
swelling and inflammation of the optic nerve at point of entrance through optical disc
progressive degeneration of the retina that affects night and peripheral vision.
group of diseases characterized by increased intraocular pressure that damages the retinal nerve fibers and optic nerve. BLOCKAGE OF FLOW OUT OF THE EYE.
open angle glaucoma (chronic)
trabecular mesh is gradually blocked causing pressure
closed angle glaucoma (acute)
fluid cannot reach trabecular mesh causing pressure in the front of the eye
progressive condition where macula is damaged, resulting in loss of vision; not blind.
blindness in one half of the visual field
excessive sensitivity to light causing headache
change in vision relating to aging
disorder in which the eyes point in a different direction or are not aligned correctly
focusing problem that occurs when lens and cornea do not bend light
images do not focus properly on the retina
uneven curvatures of the cornea causing inability to focus
dimness of vision; partial loss
"blind spot" abnormal diminished vision surrounded by an area of normal vision.
chart measures visual acuity
unit of measurement of the lens' refractive power
Pupils are Equal, Round, Responsive, to Light and Accomodation
removal of the eyeball
inward; for myopia, nearsighted
for hyperopsia; farsighted
used to reattach the detached area in a retinal detachment
: external portion of the ear
external auditory canal
: transmits sound waves to tympanic membrane
: temporal bone containing hollow air space that surrounds the middle ear.
auditory tube; equalizes air pressure
oval window; vibrations enter through here
cochlea; sound vibrations are converted into impulses
organ of Corti; receives vibrations and relays them to auditory nerve fibers.
sound waves enter the ear through the pinna and travel down the external auditory canal then strike the eardrum
eardrum vibrates and causes the auditory ossicles of middle ear to vibrate.
sound vibrations reach the inner ear.
pressure related condition caused by change in altitude; flying in an airplane, driving in the mountains.
epidermal cyst in the middle composed of epithelial cells and cholesterol
ankylosis of the bones of the middle ear; conductive hearing loss
rare chronic disorder in which the amount of fluid in the inner ear increases intermittently.
ringing, buzzing in the ear.
gradual loss of sensorineural hearing
conductive hearing loss
occurs when sound waves are prevented from passing from the air to the fluid filled inner ear; earwax buildup, infection,
sensorineural hearing loss
damage to hair cells within the ear. "nerve deafness"
weber and rinne tests
use of a tuning fork to distinguish between conductive and sensorineural hearling losses
surgical procedure in which a new opening is created in the labyrinth to restore hearing loss