Special Senses: The Eyes and Ears Flashcards
opt/i, opt/o, optic/o, ophthalm/o; receptor organs for the sense of sight
eyes
ir/i, ir/o, irid/o, irit/o; controls the amount of light entering the eye
iris
phac/o, phak/o; focuses rays of light on the retina
lens
retin/o; converts light images into electrical impulses and transmits them to the brain
retina
dacryocyst/o, lacrim/o; accessory structures of the eyes that produce, stores, and remove tears
lacrimal apparatus
acous/o, acoust/o, audi/o, audit/o, ot/o; receptor organs for the sense of hearing; also help maintain balance
ears
pinn/i; transmits soundwaves to the middle ear
outer ear
myring/o, tympan/o; transmits sound waves to the inner ear
middle ear
labyrinth/o; receives sound vibrations and transmits them to the brain
inner ear
(adnexa oculi) the structures outside the eyeball; include the orbit, eye muscles, eyelids, eyelashes, conjunctiva, and lacrimal apparatus
adnexa of the eyes
the accessory or adjoining anatomical parts of an organ
adnexa
(eye socket) the bony cavity of the skull that contains and protects the eyeball and its associated muscles, blood vessels, and nerves
orbit
occurs when the muscles of both eyes work together in coordination to make normal perception possible
binocular vision
help protect the eyeball from foreign matter, excessive light, and injuries
upper and lower eyelids, eyebrows, eyelashes
the angle where the upper and lower eyelids meet
canthus
small hairs, make up eyebrows and eyelashes
cilia
(tarsal plate) the framework within the upper and lower eyelids that provides the necessary stiffness anf shape
tarsus
the transparent mucous membrane that lines the underside of each eyelid and continues to form a protective covering over the exposed surface of the eyeball
conjunctiva
(tear apparatus) consists of the structures that produce, store, and remove tears
lacrimal apparatus
located on the underside of the upper eyelid just above the outer corner of the eye, secretes lacrimal fluid
lacrimal glands
(tears) maintain moisture on the anterior surface of the eyeball; blinking distributes the lacrimal fluid across each eyeball
lacrimal fluid
consists of a duct at the inner corner of each eye that connects tears and empty them into the lacrimal sacs; crying is the overflowing of tears from the lacrimal glands
lacrimal canal
(tear sac) an enlargement of the upper portion of the lacrimal duct
lacrimal sac
(nasolacrimal duct) the passageway that drains excess tears into the nose
lacrimal duct
(globe) a 1-inch sphere with only about 1/6 of its surface visible
eyeball
pertaining to the or sight
optic
pertaining to the eye
ocular
outside the eyeball
extraocular
within the eyeball
intraocular
(white of the eye) maintains the shape of the eye and protects the delicate inner layers of the tissue; this tough, fibrous tissue forms the outer layer of the eye, except for the part covered by the cornea
sclera
(choroid coat) the opaque middle layer of the eyeball that contains many blood vessels and provides the blood supply for the entire eye
choroid
the sensitive innermost layer that outlines the posterior segment of the eye and receives nerve impulses and transmits them to the brain via the optic nerve
retina
(aqueous fluid) fills the anterior and posterior chambers; helps the eye maintain its shape and nourishes the intraocular structures
aqueous humor
constantly filters and drains aqueous fluid
trabecular meshwork and the canal of Schlemm
(IOP) the measurement of the fluid pressure inside the eye; this pressure is regulated by the rate at which aqueous humor enters and leaves the eye
intraocular pressure
makes up 2/3 of the eyeball, lined with the retina and filled with vitreous humor
posterior segment
a soft, clear jelly-like mass that contains millions of fine fibers that help the eye maintain its shape
vitreous gel
receives images that have passed through the lens of the eye these images are converted into nerve impulses and transmitted to the brain via the optic nerve
rods and cones
the black and white receptors
rods
the color receptors
cones
(macula lutea) the clearly defined light-sensitive area in the center of the retina that is responsible for sharp central vision
macula
a pit in the middle of the macula; color vision is best in this area because it contains a high concentration of cones and no rods
fovea centralis
(blind spot) a small region in the eye where the nerve endings of the retina enter the optic nerve; called the blind spot because it does not contain any rods or cones to convert images into nerve impulses
optic disk
transmits these nerve impulses from the retina to the brain
optic nerve
the pigmented layer of the eye; it has a rich blood supply and consists of the choroid, ciliary body, and iris
uvea
located within the choroid, is a set of muscles and suspensory ligaments that adjust the thickness of the lens to refine the focus of light rays on the retina
ciliary body
the colorful circular structure that surrounds the pupil; the muscles within the iris control the amount of light that is allowed to enter the eye through the pupil
iris
the transparent outer layer surface of the eye covering the iris and pupil; the primary structure focusing light rays entering the eye
cornea
the black circular opening in the center of the iris that permits light to enter the eye
pupil
the clear, flexible, curved structure that focuses on the retina; contained within a clear capsule located behind the iris and pupil
lens
the process whereby the eyes make adjustments for seeing objects at various distances; these adjustments include contraction and dilation of the pupil, movement of the eyes, and changes in the shape of the lens
accommodation
the simultaneous inward movement of the eyes toward each other in an effort to maintain single binocular vision as an object comes nearer
convergence
the normal relationship between the refractive power of the eye and the shape of the eye that enables light rays to focus correctly on the retina
emmetropia
(refractive power) the ability of the lens to bend light rays so they focus on the retina
refraction
the ability to distinguish object detail and shape at a distance
visual acuity
a physician who specializes in diagnosing and treating the full spectrum of diseases and disorders of the eyes, from vision and correction to eye surgery
ophthalmologist
hold a doctor of optometry degree and provides primary eye care, including diagnosing eye diseases and conditions and measuring the accuracy of vision to determine whether corrective lenses are needed
optometrist
sometimes plays a role to an optometrist
certified paraoptometric
a healthcare practitioner who designs, fits, and dispenses lenses for vision correction
optician
(blepharoptosis) the drooping of the upper lid that is usually due to paralysis
ptosis
a nodule or cyst, usually on the upper lid, caused by obstruction in a sebaceous gland; a type of granuloma
chalazion
(stye) a pus-filled and often painful lesion on the eyelid resulting from an acute infection in a sebaceous gland
hordeolum
swelling of the eyelid, often at the location of the eyelash hair follicles
blepharitis
the eversion of the edge of an eyelid; usually affects the lower lid, thereby exposing the inner surface of the eyelid to irritation and preventing tears from draining properly
ectropion
the inversion of the edge of an eyelid; usually affects the lower eyelid and causes the eyelashes to tub against the cornea
entropion
swelling of the tissues surrounding the eye or eyes; this can give the face a bloated appearance and cause the eyes to be partially covered by the swollen eyelids; this swelling is associated with conditions such as allergic reaction, nephrotic syndrome, or cellulitis
periorbital edema
(pinkeye) an inflammation of the conjunctiva that is usually caused by an infection or allergy
conjunctivitis
an inflammation of the lacrimal gland caused by a bacterial, viral, or fungal infection; signs and symptoms of this condition include sudden severe pain, redness, and redness in the orbit of the eye
dacryoadenitis
bleeding between the conjunctiva and the sclera; usually caused by an injury, creates a red area over the white of the eye
subconjunctival hemorrhage
(dry eye) drying of the eye surfaces because the tear glands do not produce enough tears; this condition is often associated with aging, can also be due to systemic diseases such as rheumatoid arthritis or caused by a lack of vitamin A
xerophthalmia
an inflammation of the uvea causing swelling and irritation, complications can potentially lead to permanent vision loss
uveitis
most common form of uveitis; inflammation of the uvea affects primary structures of the front eye that is sudden onset and may last 6-8 weeks
iritis
an injury to the outer layers of the cornea
corneal abrasion
a pitting of the cornea caused by an infection or injury; can leave a cloudy scar that impairs vision
corneal ulcer
damage to the retina as a complication of uncontrolled diabetes
diabetic retinopathy
can occur as diabetic retinopathy progresses
diabetic macular edema
an inflammation of the cornea; this condition can be due to many causes, including bacterial, viral, or fungal infections
keratitis
occurs when the cornea becomes irregular and cone-shaped, causing blurring and distortion of vision
keratoconus
an inflammation of the sclera usually associated with infections, chemical injuries, or autoimmune diseases
scleritis
a condition in which the pupils are unequal in size; can be congenital or caused by a head injury, an aneurysm, or pathology of the central nervous system
anisocoria
the loss of transparency of the lens that causes a progressive loss of visual clarity; the formation of most cataracts is associated with aging; however, this condition can be congenital or due to an injury or disease
cataract
(vitreous floaters) particles of cellular debris that float in the vitreous humor and cast shadows in the retina, may be an indication of retinal detachment
floaters
the presence of what appears to be flashes of light, or flashers; often caused by damage to the eye or migraine headaches
photopsia
the contraction of the pupil, normally in response to exposure to light but also possibly due to the use of prescription or illegal drugs
miosis
the dilation of the pupil caused by diseases, trauma, and drugs
mydriasis
an involuntary, constant, rhythmic movement of the eyeball that can be congenital or caused by neurological injury or drug use
nystagmus
(choked disk) swelling and inflammation of the optic nerve at the point of entrance into the eye through the optic disk caused by increased intracranial pressure and can be due to a tumor pressing on the optic nerve
papilledema
(detached retina, retina tears) the separation of some or all of the light-sensitive retina from the choroid
retinal detachment
a progressive degeneration of the retina that affects night and peripheral vision; can be detected by the presence of dark pigmented spots in the retina
retinitis pigmentosa
a form of vasculitis that can cause a sudden vision loss, usually in one eye
temporal arteritis
a group of diseases characterized by increased intraocular pressure that causes damage to the retinal nerve fibers and the optic nerve; this increased pressure is caused by a blockage of flow of fluid out of the eye; if untreated, this pressure can cause loss of peripheral vision and eventual blindness
glaucoma
(chronic glaucoma) the trabecular meshwork gradually becomes blocked, causing a buildup of pressure; symptoms are not noticed until the optic nerve has been damaged
open-angle glaucoma
(acute glaucoma) the opening between the cornea and iris narrows so that fluid cannot reach the trabecular meshwork; this narrowing can cause a sudden increase in the intraocular pressure that produces severe pain, nausea, redness of the eye, and blurred vision; without immediate treatment, blindness can occur in as little as 2 days
closed-angle glaucoma
(MD) a gradually progressive condition in which the macula at the center of the retina is damaged, resulting in the loss of central vision but not in total blindness
macular degeneration
(double vision) the perception of two images of a single object and is sometimes a symptom of a serious underlying disorder such as MS or a brain tumor
diplopia
blindness in one-half of the visual field
hemianopia
(color blindness) the inability to distinguish certain colors in a normal manner; a genetic condition caused by deficiencies in or the absence of certain types of cones in the retina
monochromatism
(night blindness) a condition in which an individual with normal daytime vision has difficulty seeing at night
nyctalopia
excessive sensitivity to light and can be a result of migraines, excessive wearing of contact lenses, drug use, or inflammation
photophobia
the condition of common changes in the eyes that occur with aging; with age, near vision declines noticeably as the lens becomes less flexible and the muscles of the ciliary body become weaker, which results in the eyes no longer being able to focus the image properly ont he retina
presbyopia
a disorder in which the eyes point in different directions or are not aligned correctly, because the eye muscles are unable to focus together
strabismus
(cross-eyes) strabismus characterized by the inward deviation of one or both eyes
esotropia
(wall eye) strabismus characterized by the outward deviation of one eye relative to the other
exotropia
a focusing problem that occurs when the lens and cornea do not bend light so that it focuses properly on the retina
refractive disorder
any error of refraction in which images do not focus properly on the retina
ametropia
a condition in which the eye does not focus properly because of uneven curvatures of the cornea
astigmatism
(farsightedness) a defect in which light rays focus beyond the retina; this condition can occur in childhood but usually causes difficulty after age 40
hyperopia
(nearsightedness) a defect in which light rays focus in front of the retina; this condition usually occurs around puberty
myopia
a point in which, under law, an individual is considered to be blind; best-corrected vision is 20/200 or less
legal blindness
a dimness of vision or the partial loss of sight, especially in one eye, without detectable disease of the eye
amblyopia
(blind spot) an abnormal area of diminished vision surrounded by an area of normal vision
scotoma
(SC) used to measure visual acuity; the results for each eye are recorded as a fraction with 20/20 being considered normal
Snellen chart
done to determine an eye’s refractive error so that the best corrective lenses can be prescribes
refraction test
the unit of measurement of a lens’ refractive power
diopter
an examination of how the two eyes work together and is used to assess binocular vision; one eye at a time is covered while the patient focuses on an object across the room
cover test
(perimetry) performed to determine losses in peripheral vision; this test is done by having the patient look straight ahead and indicate whether or not they can see an object or flash of light when it is presented in their periphery
visual field testing
(fundoscopy) the use of an ophthalmoscope to visually examine the fundus of the eye; this examination includes the retina. optic disk, choroid, and blood vessels
ophthalmoscopy
required in preparation for the ophthalmoscopic examination of the interior of the eye; artificial enlargement of the pupils is achieved through the use of mydriatic drops
dilation
placed into the eyes to produce temporary paralysis, forcing the pupils to remain dilated even in the presence of bright light
mydriatic drops
a diagnostic procedure in which a narrow beam of light is focused onto parts of the eye to permit the ophthalmologist to examine the structures at the front of the eye, including the cornea, iris, and lens; often fluorescein staining is used to help detect foreign bodies or an infected or injured area of the eye
slit-lamp ophthalmoscopy
the application of fluorescent dye to the surface of the eye via eyedrops or a strip applicator; this dye causes a corneal abrasion to temporarily appear bright green
fluorescein staining
