Module 17 Sense Organs

Accomodation

adjustment of eye to focus object from far to near

Anterior Chamber

area behind cornea in front of lens and iris with aqueous humor

Aqueous Humor

fluid produced by ciliary body and found in anterior chamber (blood and lymph)

Biconvex

consisting two surfaces rounded, elevated and curved evenly

Choroid

middle vascular layer of eye between retina and sclera

Ciliary Body

around lens and connects iris to choroid (controls shape of lens and secretes aqueous humor)

Cone

photoreceptor cell in retina transforms light energy into nerve impulse that controls color and central vision

Conjunctiva

delicate membrane lining eyelids and covering eyeball up to cornea

Cornea

fibrous transparent layer clear tissue extends over anterior portion of eyeball

Fovea Centralis

tiny pit or depression in retina which is the region with the clearest vision

fundus of eye

posterior inner part of eye

Iris

pigmented colored layer opens and closes to all more or less light into the eye

Lens

transparent biconvex body behind pupil eye that bends light rays to bring them into focus of retina

Macula

small oval region on retina near optic disc with fovea centralis as the area of clearest vision

Optic Chiasm

point optic nerve fibers cross brain

Optic Disc

region back of eye where optic nerve meets retina and is the blind spot of eye with nerve fibers, no rods or cones and is insensitive to light

Optic Nerve

cranial nerve carrying impulses from the retina to brain

Refraction

bending light rays by cornea, lens, and fluids of eye to bring rays focus on retina

Retina

light sensitive nerve cell layer of eye with photoreceptor cells (rods and cones)

Rod

photoreceptor cell of retina for vision in low light and peripheral vision

Sclera

tough white outer coat of eyeball

Thalamus

relay center of brain, optic nerve fibers pass through thalamus to cerebral cortex

Vitreous Humor

soft, jelly material behind lens in vitreous chamber to maintain shape of eyeball

blephar/o

eyelid

conjunctiv/o

conjunctiva

cor/o

pupil

cornea/o

cornea

cycl/o

ciliary body or muscle of eye

dacry/o

tears, tear duct

ir/o, irid/o

iris

kerat/o

cornea

lacrim/o

tears

ocul/o

eye

opt/o, optic/o

vision, eye

ophthalm/o

eye

palpebr/o

eyelid

papillo/o

optic disc

phac/o, phak/o

lens of eye

pupillo/o

pupil

retin/o

retina

scler/o

sclera

uve/o

uvea

vitre/o

glassy

ambly/o

dull, dim

dipl/o

double

glauc/o

gray

mi/o

smaller, less

mydr/o

widen, enlarge

nyct/o

night

presby/o

old age

scot/o

arkness

xer/o

dry

-opia

vision

-opsia

vision

-tropia

to turn

Astigmatism

defect curvature of cornea or lens of eye

Hyperopia (Hypermetropia)

farsightness

Myopia

nearsightedness

Presbyopia

impairment of vision at old age

Cataract

clouding lens causing decreased vision

Chalazion

small, hard cystic mass of eyelid

Diabetic Retinopathy

disease retina caused by diabetes mellitus

Glaucoma

increased intraocular pressure results in damage to retina and optic nerve with loss of vision

Hordeolum

local, purulent, inflam staphylococcal infection of sebaceous glands in eyelid

Macular Degeneration

progressive damage to macula of retina

Nystagmus

repetitive rhythmic movements of one or both eyes

Retinal Detachment

two layers of retina separate from each other

Strabismus

abnormal deviation of eye

trabecul/o

small beam, rod, or plank wood

Fluorescein Angiography

intravenous injection of fluorescein dye and serial photographs of retina through dilated pupils

Optical Coherence Tomography (OCT)

noninvasive imaging technique using light waves to take cross-sectional pictures of retina

Slit Lamp Microscopy

exam anterior ocular structures under microscopic magnification

Visual Acuity Test

clarity vision assessed

Visual Field Test

measurement of entire scope vision

Enucleation

removal of entire eyeball

Laser Photocoagulation

intense focused light beam creates inflam reaction seals retinal tears and leaky retinal blood vessels

LASIK

use of excimer laser to correct errors of refraction

Phacoemulsification

cataract removal surgery ultrasonic vibrations break up lens

Scleral Buckle

suture silicone band to sclera over detached portion of retina

Vitrectomy

removal of vitreous humor

acous/o

hearing

audi/o

hearing and sense of hearing

audit/o

hearing

aur/o, auricul/o

ear

cochle/o

cochlea

myring/o

eardrum, tympanic membrane

ossicul/o

ossicle

ot/o

ear

salping/o

eustachian tube, auditory tube

staped/o

stapes (third bone of middle ear)

vestibul/o

vestibule

-acusis/-cusis

hearing

-meter

instrument measure

-otia

ear condition

Acoustic Neuroma

benign tumor arising acoustic vestibulocochlear nerve in brain

Cholesteatoma

collection of skin cells and cholesterol in sac in middle ear

Meniere Disease

disorder of labyrinth of inner ear

Otitis media

inflammation of middle ear

Otosclerosis

harden bony tissue of middle ear

Tinnitus

sensation of noises in ears without an external source