Ch 14 Special Sense Organs and the PNS (Eyes) Flashcards
consists of nerves that branch out from the brain and spinal cord
PNS
sensory nerve endings that respond to various kinds of stimulation
receptors
special sense organs
eyes, ears, skin, mouth, and nose
small dark circular structure in the center of the eye
pupil
colored portion of the eye; contracts or relaxes to control the amount of light entering the eye through the pupil
iris
tough outer layer of the eye
sclera
accessory organs of the eye (6)
muscle, fascia, eyebrow, eyelid, conjunctiva, lacrimal glands
mucous membrane lining the inner surface of the eyelid
conjunctiva
produce and store tears
lacrimal glands
refraction of light
cornea
blood supply
choroid
word to describe the refractory adjustment for close vision
accommodation
blind spot of the eye
optic disc
responsible for peripheral vision, night vision, and detection of motion
rods
responsible for color and central vision
cones
daltonism
color blindness / weakness in which the green or red receptor cones are defected; inherited, sex-linked disorder
achromatic vision
total color blindness; inability to see any color
choroid/o
choroid
chrom/o
color
conjunctiv/o
conjunctiva
corne/o, kerat/o
cornea
dacry/o, lacrim/o
tear
ir/o, irid/o
iris
ocul/o, ophthalm/o
eye
opt/o, optic/o
vision
presby/o
old or old age
pupill/o
pupil
retin/o
retina
ton/o
tone or tension
secretion of vitreous fluid, helps change the shape of lens
ciliary body
movement of the eyeball
external ocular muscles
protection for the eye
eyelid
light refraction
lens
transmission of visual info to the brain
optic nerve
transforms optic signals into nerve impulses
retina
nearsightedness; parallel rays entering the eye are focused in front of the retina
myopia
farsightedness, inability of the eyes to focus on nearby objects rays of light entering the eye are brought to focus behind the retina
hyperopia
uneven focusing of the image, resulting from distortion of the curvature of the lens or cornea
astigmatism
measurement of the intraocular pressure using a tonometer
tonometry
hyperopia and impairment of vision d/t advancing years or old age
presbyopia
agent that dilates the pupil
mydriatic
ability of the eye to adjust to variations in distance
accommodation reflex
uses fluorescein to examine movement of blood through blood vessels in the eye
fluorescein angiography
reduced vision in one eye, not correctable by glasses but by wearing eye patch
amblyopia; aka strabismus
inflammation of the eyelid
blepharitis
abnormal progressive condition of the lens, characterized by loss of transparency
cataract
inflammation of the conjunctiva
conjunctivitis; aka red eyes/pink eye
abnormal condition of inc. pressure within the eye. Prolonged pressure can damage the retina and the optic nerve
glaucoma
sty, resulting from an infected sebaceous gland of an eyelash
hordeolum
progressive deterioration of the retina associated with new vessel formation that can progress to blindness
macular degeneration
poor vision at night or in dim light
nyctalopia
excessive sensitivity of the eyes to light
photophobia
drooping of the upper eyelids
ptosis
separation of the retina from the choroid, usually resulting from a hole or tear in the retina. If detachment is not halted, total blindness of the eye ultimately results
retinal detachment
any disease of the retina
retinopathy
profound inability to see color
achromatopsia