chapter 17 eye and ear

fluorescein angiography

Intravenous injection of fluorescein followed by serial photographs of the retina through dilated pupils.

ophthalmoscopy

Visual examination if the interior of the eye.

slit lamp microscopy

Examination of anterior ocular structures under microscopic magnification.

visual acuity test

Clarity of vision is assessed

visual field test

Measurement of the area within which objects are seen when the eyes are fixed, looking straight ahead without moment of head.

enucleation

Removal of entire eyeball

keratoplasty

Surgical repair of the cornea.

laser photocoagulation

Intense, precisely focused light beam creates and inflammatory reaction that seals retinal tears and leaky retinal blood vessels.

LASIK

Use of an excimer laser to correct errors of refraction.

phacoemulsification

Ultrasonic vibrations break up lens, which then is aspirated through the ultrasonic probe.

scleral buckle

Suture of a silicone band to the sclera over a detached portion of the retina.

audiometry

Testing the sense of hearing

cochlear implant procedure

Surgical insertion of a device that allows sensorineural hearing-impaired persons to understand speech.

ear thermometry

Measurement of the temperature of the tympanic membrane by detection of infrared radiation from eardrum.

otoscopy

Visual examination of the ear canal with an otoscope.

tuning fork tets

Test the eardrum conduction using a vibration source.

Rinne test

Place vibrating fork against mastoid bone.

Weber test

Placing vibrant fork on the center of the forehead.

astigmatism

Defective curvature of the cornea or lens of the eye.

hyperopia (hypermetropia)

Farsightedness

myopia

Nearsightedness( eyeball is too long)

presbyopia

Impairment of vision as a result of old age.

cataract

Clouding of the lens, causing decreased vision.

chalazion

Small, hard, cystic mass (granuloma) on the eyelid.

diabetic retinopathy

diabetes mellitus effects: microaneurysms, hemorrhages, dilation of rental veins, and neovascularization.

macula edema

Fluid leaks from blood vessels into retina and vision is blurred.

exudates

Fluid leaks from blood and appear in the retina as yellow spots.

glaucoma

Increased intraocular pressure results in damage to the retina and optic nerve with loss of vision.

tonometry

Measures intraocular pressure to detect glaucoma.

trabeculoplasty

Laser therapy for chronic open angle glaucoma.

hordeolum (stye or sty)

Localized, purulent, inflammatory staphylococcal infection of a sebaceous gland in the eyelid.

macular degeneration

Progressive damage to the macula of the retina.

drusen

Deposits of clumps of extracellular debris in macular degeneration.

nystagmus

Repetitive rhythmic movements of one or both eyes.

retinal detachment

Two layers of retina separate form each other.

photopsia

Bright flashes of light, symptom of retinal detachment.

floaters

Black spots or filmy shapes in vision, symptom of retinal detachment.

scleral buckle

Piece of silicone sutured to sclera over the detached portion of retina to push two layers together.

pneumatic retinopexy

Procedure for sleeted retinal detachments where gas bubble s injected into the vitreous cavity to put pressure on the area of retina tear until the retina is reattached.

strabismus

Abnormal deviation of the eye. Eyes do not look in same direction. "lazy eye?"

hypertropia

strabismus: Upward deviation of one eye

hypotropia

strabismus: Downward deviation of one eye.

amblyopia

strabismus: Partial loss of vision of lazy eye.

diplopia

double vision

acoustic neuroma

Benign tumor arising from the acoustic vestibulocochlear nerve in the brain.

cholesteatoma

Collection of skin cells and cholesterol in a sac within the middle ear.

deafness

Loss of ability to hear

conductive deafness

From impairment of the middle ear ossicles and membranes transmitting sound waves into the cochlea.

Meniere disease

Disorder of the labyrinth of the inner ear; elevated endolymph pressure within the cochlea and semicircular canals.

otitis media

Inflammation of the middle ear

suppurative otitis media

Puss formation with inflammation of the middle ear.

serous otitis media

Non infectious inflammation with accumulate info serous fluid.

otosclerosis

Hardening of the bony tissue of the middle ear.

tinnitus

Sensation of noises (ringing, buzzing, whistling, booming) in the ears.

vertigo

Sensation of irregular or whirling motion wither of oneself or of external objects.

fenestrated

opened

prosthesis

artificial part

accommodation

Normal adjustment of the eye to focus on objects from far to near. The ciliary body adjusts the lens and the pupil constricts.

anterior chamber

Area behind the cornea and in front of the lens and iris. It contains aqueous humor.

aqueous humor

Fluid produced by the ciliary body and found in the anterior chamber. A humor is any body fluid including blood and lymph.

biconvex

Consisting of two surfaces that are rounded, elevated, and curved evenly, like a part of a sphere.

choroid

Middle, vascular layer of the eye, between the retina and the sclera.

ciliary body

Structure surrounding the lens that connects the choroid and iris. It contains ciliary muscles, which control the shape of the lens, and it secretes aqueous humor.

cone

Photoreceptor cell in the retina that transforms light energy into a nerve impulse. Responsible for color and central vision.

conjunctiva

Delicate membrane lining the undersurface of the eyelids and covering the anterior eyeball.

cornea

Fibrous transparent layer of clear tissue that extends over the anterior portion of the eyeball. "horny"

fovea centralis

Tiny pit or depression in the retina that is the region of clearest vision.

fundus of the eye

Posterior, inner part of the eye.

iris

Pigmented layer that opens and closes to allow more or less light into the eye.

macula

Yellowish region on the retina lateral to and slightly below the optic disc; contains the fovea centralis.

optic chiasm

Point at which optic nerve fibers cross in the brain.

optic disc

Region at the back of the eye where the optic nerve meets the retina. It is a blind spot because it contains only nerve fibers, no rods or cones.

optic nerve

Cranial nerve carrying impulses form the retina to the brain.

pupil

Central opening of the eye, surrounded by the iris, through which light rays pass.

refraction

Bending of light rays by cornea, lens, and fluids of the eye to bring the rays into focus on the retina.

rod

Photoreceptor cell of the retina essential for vision in dim light and for peripheral vision.

sclera

Tough white outer layer of the eyeball.

thalamus

Relay center of the brain. Optic nerve fibers pass through the thalamus on their way to cerebral cortex.

vitreous humor

Soft, jelly-like material behind the lens in the vitreous chamber; helps maintain the shape of the eyeball.

auditory canal

Channel that leads form the pinna to the eardrum.

auditory meatus

Auditory canal.

auditory nerve fibers

Carry impulses form inner ear to the brain. Vestibulocochlear nerve

auditory tube

Channel between the middle ear and the nasopharynx; eustachian tube

auricle

Flap of the ear; the protruding part of the external ear or pinna.

cerumen

Waxy substance secreted by external ear; earwax.

cochlea

Snail-shaped, spirally wound tube in the inner ear; contains hearing sensitive receptor cells.

endolymph

Fluid within the labyrinth of the inner ear.

eustachian tube

Auditory tube

incus

Second ossicle of the middle ear; means anvil.

labyrinth

Maze-like series of canals of the inner ear. This includes the cochlea, vestibule, and semicircular canals.

malleus

First ossicle of the middle ear; means hammer.

organ of Corti

Sensitive auditory receptor area found in the cochlea of the inner ear.

ossicle

Small bone of the ear; includes the malleus, incus, and stapes.

oval window

Membrane between the middle and inner ear.

perilymph

Fluid within the labyrinth of the inner ear.

pinna

Auricle; flap of ear.

semicircular canals

Passages in the inner ear associated with maintaining equilibrium.

stapes

Third ossicle of the middle ear; means stirrup.

tympanic membrane

Membrane between the outer and the middle ear; also called eardrum.

vestibule

Central cavity of the labyrinth, connecting the semicircular canals and a the cochlea. Contains the saccule and utricle, help maintain equilibrium.