the eye Flashcards
receptors definition
specialized cells that detect stimuli and convert them into nerve impulses
photoreceptors
receptors which detect light stimuli
position of the eye
two eyes positioned in bony eye sockets at the front of the skull
eye structure
- spherical ish and has six eye muscles which help w movement
- front of eye is covered by conjunctiva
- tear gland is above the eye
conjunctiva
thin mucous membrane which triggers a blink reflex when foreign objects enter the eye
things that protect the eye
eyelids, eyelashes
tear gland
secreted antiseptic tears that protect the conjunctiva from bacteria and dehydration
three layers of the eye
outer fibrous
middle vascular
inner light-sensitive retina
outer fibrous consists of
sclera
cornea
cornea
transparent part of the sclera, allows light rays through to the inner layers of the eye and refracts them
sclera
a strong white connective tissue that forms the outer layer of the eyeball
- protects internal parts, serves for muscle attachment
middle vasc layer consists of
choroid
ciliary body
iris
also: pupil; lens; susp ligaments
choroid
a thin, dark vascular layer
pigment absorbs excess light rays to prevent blurred images
ciliary body
a thickening of the front of the choroid, consisting of ciliary muscles and is attached to the lens by suspensory ligaments
ciliary body functions
contract and relax to change lens curvature during accomodation
iris
- round structure in the middle of the eye
- at the front of the lens and contains pigments to give it color
pupil
opening in the middle of the iris through which light rays enter the eye