eye anterior
organs,hollowed out bony socket in anterior cranium
eye posterior
composed of optic nerve,arteries,and veins
bony orbit
contains fat that cushions/protects eye.
eyelid
protects tissues,refreshes layer of ttears to keep surface moist & preventforeign substances from entering eye.
sebaceous glands
at the eyelids secrete oil to keep tears in the eye.
eyelashes
catch substances before they enter the eye
lacrimal gland
continually produces tears through lacrimal ducts.tears contaiin antibacterial enzyme to prevent infections.
conjunctiva
mucus membrane covers inside of eyelids and across anterior surface produces clear mucus allows eyelids to slide easily across the surface of the eye with each blink
sclera
tough fibrous connective tissue,white of the eye protects internal structure maintain shape,site of attachment for all that move the eye changes into layer ( cornea)
cornea
allows light to enter , it bends( refracts) rays of light contains no blood vessels or capillaries, has nerves and is most senstitve area on anterior surface.
iris
genectically determined center of pupil allows light rays to enter the eye
miosis
in bright light muscles in the iris contract to constrict ( decrease diameter) of pupile
mydriasis
in dim light muscles in the iris relax to dialate (increase diameter)
choroid
spongy membrane of blood vessels, middle layer between sclera and retina. supplies blood to the entire eye.
ciliary body
an extension of the choroid that attaches ligaments that hold lens inplace behind the iris, contains muscles that contract and relax to change shape of the lens to focus light rays coming through the pupil ,produces aqueous humor.
lens
clear flexible disk made of protein molecules becomes thicker or ore rounded for near vision or thinner and flatter for far vision,enclosed in lens capsule, a clear membrane.
anterior chamber
small space between cornea and iris
posterior chamber
narrow space posterior to iris
aqueous humor
clear watery fluid produced conrinually by ciliary body and csarries nutrients and oxygen to cornea and lens,the rate of production equals rate of drainage
posterior cavity
largest space between the lens and back of eye, filled with vitreous humor that helps maintain shpae of eye.
extraocular muscles
control movenment attached to the sclera ,ttendons under voluntary control through nerve impulses
cornea
transparant anterior part
lens
structure that chanes shape to focus light rays
fovea
small depression in retina with best vision
rods
light sensitive cells that function in daytime and nighttime vision
accomodation
change in the shape of the lens as the muscles of the ciliar body contract or relax to move the suspensory ligaments to the lens accommod/o = to adapt
anterior chamber
aqueous humor circulates through it
aqueous humor
clear watery fluid produced by the ciliary body,it circulates through posterior and anterior chambers and takes nutrients and oxygen to the cornea and lens.it drains through the tribecular network
carnuncle
red triangular tissue at the medial corner fo the eye
choroid
spongy membrane of blood vesels that begins at the irid and continues around the eye, in the posterior cavity it is the middle layer between sclera and retina
ciliary body
extension of the choroid layer that lies posterior to teh iris it has suspensory ligamnets that holf the lens in place . when the ciliary body contracts and relaxes it changes the shape of the lens. it also produces aqueous humor.
cones
light sensitive cells in the retina that detect color. there are three diferent types of cones that respond to either red light, green light, or blue light
conjunctiva
delicate transparent mucus membrane that covers the inside eyelids and the anterior surface of the eye . it produces clear wataerry mucus.
cornea
transparent layer over the anterior part to the eye. this is the same layer that was prebiiously the white sclera. the transitional area where the change occurs is the limbus
eye
optic globe
eyelids
pair of fleshy structures that blink to keep the surface of the eye moist with tears and prevent foetign sucstances from entering the eye.they contain the eyelashes and sebaceous glands.
fovea
small depersssion in the center of the macula . it is the area of sharpest visionand lies directy opposite the pupil.
fove/o=small depressed area
fundus
general word for the retina because it is the area that is furthest from the opening( pupil)
fund/o=part furtherst from the opening
iris
circular colored structure around the pupil. the muscles of th iris contract or realx to decrease or increase the diameter of the pupil. this is under involuntary control by the oculomotor nerve ( cranial nerve 3) color is determined by genectics.
irid/o=
lacrimal gland
gland in the superior-lateral aspect of the eye. it produces and secrets tears through the lacrimal duct. the lacrimal glands produce tears when stimulated by the facial nerve ( cranial nerve 7)
lacrim/o=tears
dacry/o=lacrimal sac,tears
lacrimal sac
structure that collects tears as hey fdrain from the medial aspect of the eye . it empties into the nasolacrimal duct.
lacrim/o=tears
lens
clear flexible disk behind the pupil. it is surrounded byt the lens capsule . the muscles of the ciliary body change teh lens shape (accomodation) to focus light rays on the retina.
lenticul/o=lens of the eye
lent/o=lens of the eye
phac/o=lens of the eye
lens capsule
clear membrane that surrounds that surrounds the lens
capsul/o=enveloping structure
limbus
border where the white opaque sclera becomes the transparent cornea of=ver the eye becomes the transparent cornea ovet the anterior aspect of the eye
macula
dark yellow orange area with indistinct edges on the retina. it contains the fovea
macul/o=small area or spot
miosis
contraction of the iris muscle to constrict (reduce size of) the pupil and limit the amount of light entering the eye.
mi/o=narrowing
mydriasis
relaxation of the iris muscle to kilate (inlarge the size of) the pupil and increase the amont oof light entering the eye
mydr/o=widening
nasolacrimal duct
structure that carries tears from the lacrimal sac to the inside of the nose
optic disk
bright yellow white circle on the retina where the optic nerve and retinal arteries enter and the retinal veins leave the posterior cavity .it cannot recieve sensory information and is known as the blind spot
optic nerve
cranial nerve 2 it enter the posterior eye at the otci disk. it is a sensory nerve that carries sensory information of visual images from the rods and cones of the retina. at the optic chiasm in the brain part of each optic nerve crosses over to join the
orbit
bony socket in the cranium that surrounds all but the anterior part of the eye
posterior cavity
large space between the lens and the retina. it is filled with vitreous humor cav/o=hollow space
posterior chamber
very narrow space posterior to the iris. aqueous humor circulates throught it
pupil
dark round central opening int eh iris that lalows light rays to enter the internal eye. constriction and dilation of the pupil is under invountary control throught nerve impulses to teh muscles of the iris from the oculomotor nerve (cranial nerve 3)
retina
layer of tissue that lines posterior cavity. it contains rods and cones . landmarks on the retina include the optic disk, and the macula
rods
light sensitive cells in teh retina. they detect black and white and dunction in daytine and nightitme vision
sclera
white opaque tough fibrous connetive tissue that forms the outer layer around most of the eye. it is also known as the white of the eye
stereoscopic vision
three demensional vision with depth and distance perception
stere/o=three dimensions scop/o=examine
thalamus
relay station in the brain that recieves sensosry info from the optic tracts and sends it to the midbrain and to teh visual cortex in the occipital lobes of the brain.
tribecular meshwork
interlacing fibers through which the aqueous humor drains . it is all around the iris where the edge of teh iris meets the cornea nd forms and angle
uvea
collective word for the iris,choroid,and ciliary body . it is also known as the uveal tract
visual cortex
area in the right and left occipital lobes of the brain that processes vision . it merges the imaages sffrom each eye to cteate a single image then turns the image right side up and facing in the direction of the original object. vis/o=sight vision
vitreous humor
clear gel llike substance theat fills the posterior cavity of the eye vitre/o =transparent substance
blepharitis
inflammation of the eyelids characterized by redness and swelling and dried crusts
blepharoptosis
drooping of the upper eyelid from excessive fat or sagging of the tissues. treatment blephpharoplasty.
ectropin
weakening of connective tissue in lower eyelid
ec=out outward trop/o=haveing an infinity for stimulating turning ion=action ,condition
entropion
weakening of the muscle in the lower eyelid.
hordeolum
red painful swelling or a pimple containing pus on the eyelid. caused by bacterial infection(staphylococcus) in a sebaceous gland ,also known as a stye, when the acute infection dies sometimes the horedulum becomes a chalazion, a chronically inflammed and
dacryocystitis
bacterial infection of lacrimal sac,tender and contains pus
xerophthalmia
insuffient procuction of tears,
conjunctivitis
inflammed reddened or swollen conjunctiva with dialated blood vessels in the sclera