eye - unit 5 Flashcards
protects eye from sweat. helps shade eyes. hair follicles above eye.
eyebrow
protects the eye from objects, blinking reflex, helps shade eys, contains eyelashes (“eyelids”)
palpabrae
infection of the oil gland connected to eyelash
stye
membrane infront of eyeball, it folds and lines the eyelid. secretes mucous, protects eyes, contains small blood vessels
conjuctiva
“pink eye” inflammation of conjunctiva from infection
conjuctivitis
“tear glands” in eye socket above eyeball. secretes tears
lacrimal gland
contain h20, mucous, and lysozyme. helps lubricate eye, prevent infection, and displays emotion.
tears
drains tears, found beneath skin of nose
lacrimal sacs
drains tears from lacrimal sacs into nasal cavity
nasolacrimal duct
6 muscles that stabilize/hold/allow movement of eye.
extrinsic eye muscles
3 layers of the eyeball
fibrous tissue, vascular tissue, and sensory tunic
outer layer of the eyeball
fibrous tunic
two parts of the fibrous tissue
sclera and cornea
fibrous tissue. in rear portion of eye, white dense irregular CT that contains blood vessels. provides strength and spherical structure, anchors the extrensic eye muscles
sclera
fibrous tissue. front shield of eye, transparent. only place in body to not get nutrition from blood and not be effected by the immune system. it bends light to help focus light into retina.
cornea
middle layer of the eyeball
vascular tissue
4 parts of the vascular tissue
choroid, ciliary body, iris, pupil
vascular tissue. rear portion, dark brown (high melanin). onsorbs light that passes through retina (prevents light scattering/reflecting)
choroid
vascular tissue. infront of choroid, dark brown ring with smooth muscles that attach to lens via suspensory ligaments. filters blood + forms aqueous humor that flows through front compartment
ciliary body
vascular tissue. ring of smooth muscle in front of lens, surrounds pupil, regulates amount of light passing, contains melanocytes and melanin. gives rise to eye color.
iris
hole in middle front of eye that allows light in pass through to lens
pupil
when iris increases pupil diameter
pupil dialation
when iris decreases pupil diameter
pupil constriction
deepest layer of the eyeball. contains photoreceptor cells and sensory neurons.
sensory tunic
two parts of sensory tunic
optic disc, macula lutea
sensory tunic. blind spot. axons of retinas sensory neurons exit eyeball and form optic nerve. no photoreceptor cells. light projected here is invisible.
optic disc
sensory tunic. round patch in retina that has increase number of cone photoreceptor cells, light is focused.
macula lutea
two types of photoreceptor cells
rods and cones.
photoreceptor cell. gives rise to grayscale vision.
rods
photoreceptor cell. gives rise to color vision.
cones
made of transparent (clea) crystalized cells, behind iris and pupil. attached to cicilary body via suspensory ligaments which alter lens shape via contraction
lens
clear water-like fluid formed by filtration of blood
aqueous humor
gel-like fluid which holds retina in place
vitreous humor
3 eye diseases
cataract, glaucoma, macula degeneration
eye disease. clouding of lens.
cataract
eye disease. damige to optic nerve/sensory nuerons of retina
glaucoma
eye disease. photoreceptors in macula lutea die.
macula degeneration
to view a ____ object, your iris contracts and pupil constricts. lens buldge to inc bending of light.
close
to view a ____ object, your iris contracts and pupil dialate. lens flatten to dec bending of light.
far
3 types of vision conditions
nearsightedness, farsightedness, astigmatism
vision condition. person cannot see far away. long oblong eye so lens cant flatten enough.
nearsightedness
vision condition. person cannot see up close. wide oblong eye so lens cant buldge.
farsightedness
vision condition. irregular curvature of eye’s cornea
astigmatism
near point of vision is
how close you can focus on an object. inc with age.
genetic condition in which you lack a photoreceptor cone type
colorblindness
down-regulation of photoreceptors
photobleaching
