21 terms

parts of the eye and their functions

A&P 2 Lab Test 1
thin transparent mucous membrane; folded back upon itself; covers only the white of the eye; keeps eye from dryng out
transparent bulge in the front of the eye, curved, begins refraction;
colored portion of the eye; smooth muscle; causes dialation and constriction of the pupil; by doing so it regulates the amount of light entering the pupil, first ring of tissue from pupil;
anterior chamber
just behind the cornea, full of aqueous humor;
aqueous humor
clear, watery fluid, made by ciliary body; keeps cornea bulged out in front as well as maintenance of intra ocular pressure; made and contiually absorbed;
space or black hole through which the light passes; can be eliptical in nature;
transparent and elastic, continues refraction and focusing onto the retina; held in place by the suspensory ligaments which are operated by the ciliary body; has a convex shape;
suspensory ligaments
attached to the lens; it, along with the ciliary body will cause accomodation (adjustments the eye makes for near and far vision)
ciliary body
second ring of tissue from pupil , accommodation and forms aqueous humor, smooth muscle;
posterior chamber
full of vitreous humor
vitreous humor
jelly-like; made only once; maintenance of intraocular pressure which will keep the eyeball from collapsing;
the outside part of the eye wall; very tough, white, extrinsic eye muscles attach to it;
choroid layer
second part of the eye wall; brown or black pigmented to prevent reflection by absorbing stray light rays;
third part of the eye wall; contains rods and cones; photoreceptor cells; light rays are focused on it;
optic disk
blind spot; area where the retina leaves the eye and becomes the optic nerve; no rods or cones here, thus the blind spot;
optic nerve
cranial nerve II (2); carries the nerve impulse to the thalamus and then to the occipital lobe of the cerebrum, where vision is located;
macula lutea
part of the retina; yellow disk which is lateral to the blind spot;
fovea centralis
part of the retina; found in the center of the macula lutea; a place for daytime, color and distinct vision; contains only cones;
fibrous tunic
cornea and the sclera make up which tunic?
vascular tunic
pupil, iris, choroid and ciliary body make up which tunic?
sensory tunic (retina)
fovea centralis, optic disk, macula lutea