Language of Medicine - Chapter 17 Flashcards
Special Sense Organs
define pupil
central, dark opening of the eye, surrounded b coloured portion of eye
define iris
coloured part of the eye
define conjunctiva
membrane lining he inner surfaces of the eyelids + anterior portion of the eyeball over the white of the eye, it is clear + almost colourless except blood vessels
what is conjunctivitis?
blood vessels dilate when the eye is infected or inflamed by allergies
define cornea
fibrous, transparent tissue that extends like a dome over the pupil + iris, avascular
function = bend or refract the rays of light so they focus properly on sensitive receptor cells in posterior part of eye
define sclera
white portion of the eye
define choroid
dark brown membrane inside inside sclera, contains blood vessels that supply nutrients to eye
define ciliary body
anterior portion of the eye
define uvea
iris + ciliary body are known as uvea
define lens
behind the pupil + bends / refracts the light rays
define accommodation
refractory adjustment to ficus on an object from far to near
define aqueous humour
fluid secreted by ciliary body
define anterior chamber
houses aqueous humour
define virtuous chamber
posterior cavity of the eye which is a large region behind the lens filled vitreous humour
define vitreous humour
soft, jelly like material vitreous humour + maintains the shape of eyeball - not constantly re-formed
define retina
thin, delicate, and sensitive nerve layer of the eye
define rods + cones
rods = ~120 million rods in retina - function in B&W color
cones = ~6.5 million cones in retina - function in bright levels of light + responsible of color + central vision, 3 different cones: red, green, blue
define optic nerve
initiate nerve impulses that travel from eye to brain
define optic disc
region in the eye where the optic nerve meets the retina
define macula
small, oval area of retina adjacent to the optic disc
define fovea centralis
central depression which is composed largely of cones + is the location of the sharpest vision of eye
define fundus of eye
posterior, inner part is visualized through the ophthalmoscope
define left visual field
“purple area” - sensitive cells (rods + cones) in the right half of retina are stimulated
define right visual field
“orange color” - rods + cones are stimulated in left hand of each retina
define optic chiasm
nervous impulses travel along optic nerve fibres + each retina + ten merge to form optic chaism
define optic tract
fibers from right half of each retina form optic tract which leads to thalamus, to right visual cerebral cortex
what is hemianopsia?
loss of vision which occurs in both eyes on the contralateral (opposite side) visual field
in order what is the pathway of light through the eye?
cornea, anterior chamber and aqueous humour, pupil, lens, virtuous chamber + vitreous humour, retina (rods + cones), optic nerve fibres, optic chiasm, thalamus, cerebral cortex (occipital lobe)
aque/o
water
blephar/o
eyelid
conjunctiv/o
conjunctiva
cor/o
pupil
corne/o
cornea
cycl/o
ciliary body or muscle of the eye
dacry/o
tears, tear duct
ir/o
irid/o
iris (coloured portion of the eye)
kerat/o
cornea
lacrim/o
tears
ocul/o
eye
ophthalm/o
eye
opt/o
optic/o
eye, vision
palpebr/o
eyelid
papill/p
optic disc; nipple like
phac/o
phak/o
lens of eyelid
pupill/o
pupil
retin/o
retina
scler/o
sclera (white part of the eye); hard
uve/o
uvea; vascular layer of the eye (iris, ciliary body, + choroid)
vitre/o
glassy
ambly/o
dull, dim
dipl/o
double
glauc/o
grey
mi/o
smaller, less
mydr/o
widen, enlarge
nyct/o
night
phot/o
light
presby/o
old age
scot/o
darkness
xer/o
dry
–opia
vision
–opsia
vision
–tropia
to turn
define pinna / auricle
sound waves enter through here, projecting part or flap of ear
define external auditory meatus (auditory canal)
leads from pinna + is lined with numerous glands that secrete a yellowish, brown, waxy substances called cerumen
what does cerumen do?
lubricates + protects ear canal
define tympanic membrane (eardrum)
sound waves travel through auditory canal + strike a membrane between the outer + middle ear called eardrum
what do ossicles do and what are the 3 ossicles?
eardrum vibrates + moves 3 small bones (ossicles), that conduct sound waves through the middle
3 ossicles: malleus, incus, stapes
define auditory / eustachian tube
canal leading from middle ear to pharynx
define labyrinth
in inner ear, circular maze structure
define cochlea
in inner ear, snail shaped structure + contains liquids called perilymph + endolymph
define organ of Corti
sensitive auditory receptor
define auditory nerve fibers
in organ of Corti, tiny hair cells receive vibrations from auditory liquids + relay the sound waves to auditory nerve fibres which is where sounds are heard
define vestibule
connects cochlea (for hearing)
define semicircular canals
3 circles (for balance)
what is the pathway of sound vibrations from outer ear to the brain?
pinna, external auditory canal, tympanic membrane, malleus, incus, stapes, oval window, cochlea, auditory liquids + receptors in the organ of Corti, auditory nerve fibres, cerebral cortex
acous/o
hearing
audi/o
hearing; the sense of hearing
audit/o
hearing
aur/o
auricul/o
ear
cochle/o
cochlea
mastoid/o
mastoid process
myring/o
eardrum, tympanic membrane
ossicul/o
ossicle
ot/o
ear
salping/o
Eustachian tube, auditory tube
staped/o
stapes (3rd bone in middle ear)
typman/o
eardrum, tympanic membrane
vestibul/o
vestibule
–acusis
–cusis
hearing
–meter
instrument to measure
–otia
ear condition
