Ch. 11 Special Senses Flashcards
adnexa of the eyes (6)
the structures outside the eyeball, including the orbit, eye muscles, eyelids, eyelashes, conjunctiva, and lacrimal apparatus
adnexa
appendages or accessory structures of an organ
orbit
eye socket
binocular vison
both eyes working together
canthus
the angle where the upper and lower eyelids meet
tarsus
the framework within the upper and lower eyelids that provides the necessary stiffness and shape
cilia
small hairs, in this case the eyelashes
conjunctiva
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
lacrimal apparatus
the structures that produce, store, and remove tears
lacrimal glands
secrete lacrimal fluid (tears), located on the underside of the upper eyelid, just above the outer corner of each eye
lacrimal fluid
tears, maintain moisture on the anterior surface of the eyeball, blinking distributes
lacrimal canal
duct at the inner corner of each eye, which collect tears and empty them into the lacrimal sacs
lacrimal sac
enlargement of the upper portion of the lacrimal duct
lacrimal duct
passageway that drains excess tears into the nose
optic
pertaining to eye or sight
ocular
pertaining to the eye
extraocular
outside the eyeball
intraocular
within the eyeball
sclera
white of the eye, maintains the shape of the eye and protects the delicate inner layers of tissue, tough, fibrous tissue
choroid
opaque middle layer of the eyeball that contains many blood vessels and provides blood supply for the entire eye
retina
the sensitive innermost layer that lines the posterior segment of the eye, receives nerve impulses and transmits them to the brain via the optic nerve
trabecular meshwork and canal of Schlemm
constantly filters and drains aqueous fluid, which maintains the pressure of the eye
intraocular pressure (IOP)
measurement of the fluid pressure inside the eye
vitreous gel
soft, clear, jelly-like mass that contains millions of fine fibers
Rods and cones
receive images that have passed through the lens of the eye
Rods-black and white
Cones-color
macula
clearly defined yellow area in the center of the retina which is the area of sharpest central vision
fovea centralis
a pit in the middle of the macula, color vision is best in this area bc it contains a high concentration of cones and no rods
optic disk
blind spot, small region in the eye where the nerve endings of the retina enter the optic nerve, contains no rods or cones to convert images into nerve impulses
optic nerve
transmits nerve impulses from the retina to the brain
uveal tract
the pigmented layer of the eye, which has a rich blood supply and consists of the choroid, ciliary body, and iris
ciliary body
set of muscles and suspensory ligaments that adjust the thickness of the lens to refine the focus of light rays on the retina
iris
colorful muscular layer of the eye that surrounds the pupil, muscles within the iris control the amount of light that is allowed to enter the eye through the pupil
cornea
the transparent outer surface of the eye covering the iris and pupil, primary structure focusing light rays entering the eye
pupil
black circular opening in the center of the iris that permits light to enter the eye
lens
clear, flexible, curved structure that focuses images on the retina
accommodation
process whereby the eyes make adjustments for seeing objects at various distances
convergence
the simultaneous inward movement of the eyes toward each other, occurs in an effort to maintain single binocular vision as an object comes nearer
emmetropia
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
refraction
the ability of the lens to bend light rays so they focus on the retina
visual acuity
the ability to distinguish object details an shape at a distance
ophthalmologist
dr who specializes in disorders of the eyes and vision
optometrist
hold Dr. of optometry degree and specializes in measuring the accuracy of vision to determine whether corrective lenses are needed
blepharoptosis
drooping of the upper eyelid that is usually due to paralysis
chalazion
localized swelling inside the eyelid resulting from obstruction of a sebaceous gland
ectropion
the eversion of the edge of an eyelid
entropion
inversion of the edge of an eyelid
hordeolum
stye, a pus-filled lesion on the eyelid resulting from an infection in a sebaceous gland
periorbital edema
swelling surrounding the eye or eyes
conjunctivitis
pinkeye, inflammation of the conjunctiva that is usually caused by an infection or allergy
dacryoadenitis
inflammation of the lacrimal gland that can be caused by a bacterial, viral, or fungal infection
subconjunctival hemorrhage
bleeding btw the conjunctiva and the sclera, usually caused by injury, creates a red area over the white of the eye
xerophthalmia
dry eye, drying of eye surfaces including the conjunctiva
pterygium
benign growth on the cornea that can become large enough to distort vision
synechia
an adhesion that binds the iris to an adjacent structure such as the lens or cornea
anisocoria
condition in which the pupils are unequal in size
PERRLA
pupils are equal, round, responsive to light and accommodation, diagnostic abbreviation
nystagmus
involuntary, constant rhythmic movement of the eyeball that can be congenital or caused by a neurological injury or drug use
papilledema
swelling and inflammation of the optic nerve at the point of entrance into the eye through the optic disk
retinitis pigmentosa
progressive degeneration of the retina that affects night and peripheral vision
glaucoma
group of disease characterized by increased intraocular pressure that cause damage to the retinal nerve fibers and the optic nerve
open-angle glaucoma
chronic, most common form, trabecular meshwork gradually becomes blocked, and this causes a buildup of pressure
closed-angle glaucoma
acute, the opening btw the cornea and it is narrows so that fluid cannot reach the trabecular meshwork. sudden increase in pressure causes pain, redness and blurred vision, can cause blindness in 2 days
macular degeneration
gradually progressive condition in which the macula at the center of the retina is damaged, resulting in the loss of central vision, but not total blindness
diplopia
double vision
hemianopia
blindness in one-half of the visual field
monochromatism
color-blindness
nyctalopia
night blindness
presbyopia
the condition of common changes in the eyes that occur with aging
strabismus
disorder in which the eyes point in different directions
esotropia
cross-eyes
exotropia
walleye, outward deviation of one eye relative to the other
refractive disorder
focusing problem that occurs when the lens and cornea do not bend light so that is focuses properly on the retina
ametropia
any error of refraction in which images do not focus properly on the retina
astigmatism
condition in which the eye does not focus properly bc of uneven curvatures of the cornea
hyperopia
farsightedness, defect in which light rays focus beyond the retina
myopia
nearsightedness, defect in which light rays focus in front of the retina
amblyopia
dimness of vision or the partial loss of sight, especially in one eye, without detectable disease of the eye
scotoma
blind spot, abnormal area of absent or depresses vision surrounded by an area of normal vision
diopter
unit of measurement of a lens’ refractive power
refraction
examination procedure to determine an eye’s refractive error
ophthalmoscopy
visual examination of the fundus of the eye with an ophthalmoscope
mydriatic drops
medicated drops that produce temporary paralysis
slit-lamp ophthalmoscopy
diagnostic procedure in which a narrow beam of light is focused onto parts of the eye to examine the structures at the front of the eye
tonometry
measurement of intraocular pressure
fluorescein staining
fluorescent dye that causes a corneal abrasion to appear bright green
fluorescein angiography
radiographic study of the blood vessels in the retina of the eye following the IV injection of a fluorescein dye as a contrast medium
visual field testing
performed to determine losses in peripheral vision
tarsorrhaphy
the partial, or complete, suturing together of the upper and lower eyelids
radial keratotomy
incisions are made in the cornea to cause it to flatten, which brings the focal point of the eye closer to the retina and improves distance vision
phacoemulsification
the use of ultrasonic vibration to shatter and remove the lens clouded by a cataract
pseudophakia
an eye in which the natural lens has been replaced with an intraocular lens
laser iridotomy
uses a focused beam of light to create a hole in the iris, used to treat closed-angle glaucoma
laser trabeculoplasty
used to treat open-angle glaucoma by creating opening in the trabecular meshwork
LASIK
Laser-Assisted in Situ Keratomileusis
photocoagulation
the use of lasers to treat some forms of wet macular degeneration by sealing leaking or damaged blood vessels
pinna
the external portion of the ear-catches sound waves and transmits them into the external auditory canal
external auditory canal
transmits sound waves from the pinna to the tympanic membrane of the middle ear
cerumen
earwax, protects by trapping anything that comes into the ear
tympanic membrane
eardrum, transmits the sound by vibrating
mastoid bone cells
hollow air spaces located in the mastoid process of the temporal bone
auditory ossicles
three small bones found in the middle ear, they transmit sound waves from the eardrum to the inner ear by vibration
what are the three auditory ossicle bones?
- malleus-aka hammer
- incus-aka anvil
- stapes-aka stirrup
eustachian tubes
aka auditory tubes, narrow tubes that lead from the middle ear to the nasal cavity and throat, they equalize the air pressure in the middle ear with that of the outside t
inner ear
aka labyrinth, contains the sensory receptors for hearing and balance
oval window
located under the base of the stapes, it is the membrane that separates the middle ear from the inner ear
cochlea
snail-shaped, fluid-filled structure that forms the inner ear
cochlear duct
fluid-filled cavity within the cochlea that vibrates when sound waves strike it
organ of Corti
receives the vibrations from the cochlear duct and replays them to the auditory nerve fibers
semicircular canals
contain the liquid endolymph and sensitive hair-like cells, help with equilibrium
acoustic nerves
transmit info to the brain, and the brain sends messages to the muscles in all parts of the body to ensure that equilibrium is maintained
air conduction
the process by which sound waves enter the ear through the pinna
bone conduction
occurs as the eardrum vibrates and moves the auditory ossicles
sensorineural conduction
occurs when sound vibrations reach the inner ear
impacted cerumen
an accumulation of earwax that forms a solid mass by adhering to the walls of the external auditory canal
otalgia
earache
barotrauma
pressure-related ear discomfort that can be caused by pressure changes
infectious myringitis
contagious inflammation that causes painful blisters on the eardrum
patulous eustachian tube
distention of the eustachian tube
otitis media
an inflammation of the middle ear
acute otitis media
usually associated with an upper respiratory infection and is most commonly seen in children, can lead to a ruptured eardrum
serous otitis media
a fluid buildup in the middle ear that can follow acute otitis media or can be caused by obstruction of the eustachian tube
acute purulent otitis media
a buildup of pus within the middle ear due to infection
Meniere’s syndrome
rare chronic disease in which the amount of fluid in the inner ear increases intermittently, producing attacks of vertigo, fluctuating hearing loss, and tinnitus
tinnitus
a ringing, buzzing, or roaring sound in one or both ears
conductive hearing loss
occurs when sound waves are prevented from passing from the air to the fluid-filled ear, caused by earwax buildup, infection, fluid, punctured eardrum, otosclerosis, and scaring
sensorineural hearing loss
nerve deafness, develops when the auditory nerve or hair cells in the inner ear are damaged
hertz
measure of sound frequency that determines how high or low a pitch is
decibel
measurement of the loudness of sound
tympanometry
the use of air pressure in the ear canal to test for disorders of the middle ear
fenestration
surgical procedure in which a new opening is created in the labyrinth to restore hearing
