Chapter 16 Flashcards
(196 cards)
accommodation
adjustment of the eye for various distances so that images focus on the retina of the eye
acuity
clearness or sharpness of a sensory function
humor
any fluid or semifluid of the body
labyrinth
series of intricate communicating passages
opaque
substance or surface that neither transmits nor allows the passage of light
perilymph
fluid that very closely resembles spinal fluid but is found in the cochlea
photopigment
light-sensitive pigment in the retinal cones and rods that absorbs ight and initiates the visual process; also called visual pigment
refractive
ability to bend light rays as they pass from one medium to another
stereopsis
depth perception provided by visual information derived from two eyes located in slightly different positions so that each produces its own unique view of an object
fibrous tunic
the outermost layer of the eyeball that serves as a protective coat for the more sensitive structures beneath; including:
1) sclera
2) cornea
3) conjunctiva
sclera
provides strength, shape, and structure to the eye; it bulges forward in front of the eye to create the cornea
cornea
transparent body structure that allows light to enter the interior of the eye; does not contain capillaries and must rely on eye fluids for nourishment
conjunctiva
the outer surface of the eye that lines the eyelids; produces tears and mucus
vascular tunic (uvea)
middle layer; including:
1) choroid
2) iris
3) ciliary body
choroid
provides blood supply for the entire eye; prevents extraneous light from entering the eye; made up of:
1) iris
2) ciliary body
iris
a colored, contractile membrane with a perforated center; regulates the amount of light entering the eye through the pupil
pupil
perforated cented of the iris through which light enters through
ciliary body
a circular muscle that produces aqueous humor; is attached to a capsular bag that holds the lens and the suspensory ligaments
lens
allows the eye to focus on an image by being made thicker and thinner by the ciliary body
suspensory ligaments
holds the lens in place
eye
a globe-shaped organ composed of three distinct tunics/layers:
1) fibrous tunic
2) vascular tunic
3) sensory tunic
sensory tunic
innermost layer of the eye consisting of the delicate, double-layered retina
retina
responsible for the reception and transmission of visual impulses to the brain; contains two types of receptors; consists of two separate layers
rods
visual receptors that function in dim light and produce black-and-white vision