Flashcards in Chap 17, The Eye, Vocabulary Deck (25)
Normal adjustment of the eye to focus on objects from far to near. The ciliary body adjusts the lens (rounding it) and the pupil constricts. When the eye focuses from near to far, the ciliary body flattens the lens and the pupil dilates.
Area behind the cornea and in front of the lens and iris. It contains aqueous humor.
Fluid produced by the ciliary body and found in the anterior chamber. A humor is any body fluid, including blood and lymph.
Consisting of two surfaces that are rounded, elevated, and curved evenly, like part of a sphere. The lens of the eye is a biconvex body.
Middle, vascular layer of the eye, between the retina and the sclera.
Structure surrounding the lens that connects the choroid and iris. It contains ciliary muscles, which control the shape of the lens, and it secretes aqueous humor.
Photoreceptor cell in the retina that transforms light energy into a nerve impulse. Cones are responsible for color and central vision.
Delicate membrane lining the undersurface of the eyelids and covering the anterior eyeball.
Fibrous transparent layer of clear tissue that extends over the anterior portion of the eyeball.
Tiny pit or depression in the retina that is the region of clearest vision.
fundus of the eye
Large posterior, inner part of the eye that is visualized with an ophthalmoscope.
Pigmented (colored) layer that opens and closes to allow more or less light into the eye. The central opening of the iris is the pupil.
Transparent, biconvex body behind the pupil of the eye. It bends (refracts) light rays to ring them into focus on the retina.
Yellowish region on the retina lateral to and slightly below the optic disc; contains the fovea centralis, which is the area of clearest vision.
Point at which optic nerve fibers cross in the brain.
Region of the back of the eye where the optic nerve meets the retina. It is the blind spot of the eye because it contains only nerve fibers, no rods or cones, and is thus insensitive to light.
Cranial nerve carrying impulses from the retina to the brain (cerebral cortex).
Central opening of the eye, surrounded by the iris, through which light rays pass. It appears dark.
Bending of light rays by the cornea, lens, and fluids of the eye to bring the rays into focus on the retina. Refract means to break (-fract) back (re-).
Light-sensitive nerve cell layer of the eye containing photoreceptor cells (rods and cones).
Photoreceptor cell of the retina essential for vision in dim light and for peripheral vision.
Tough, white outer coat of the eyeball.
Relay center of the brain. Optic nerve fibers pass through the thalamus on their way to the cerebral cortex.
Soft, jelly-like material behind the lens in the vitreous chamber; helps maintain the shape of the eyeball.