The Senses Part 2 Flashcards
“White of the eye”
Part of the front part of the sclera
Part of the sclera referred to as the window of the eye
Cornea
Inflammation of the cornea
Keratitis
Cornea lies over what?
Iris
What color is the cornea
Transparent
Conjunctiva
A mucus membrane that lines the eyelids and covers the sclera in front
Inflammation oft the conjunctiva
Conjunctivitis
Conjunctivitis is generally caused by?
Bacterial or viral infections, allergies, or environmental factors
What three layers of tissue form the eyeball?
Sclera, choroid, retina
The conjunctiva is kept moist by tears formed in the?
Lacrimal gland
Procedure that eliminates near sightedness by placing incisions around the cornea
Radial keratotomy
Middle layer of the eyeball
Choroid
What is the function of the choroid
Contains dark pigments that prevent the scattering of incoming light rays.
Two involuntary muscles that make the outer layer of the choroid
Iris and ciliary muscle
Black center of the iris that is a hole in the donut shaped muscle
Pupil
When pupils dilate due to contracting of the iris, what happens to the pupil
The pupil dilates allowing more light into the eye
Where does the lens of the eye lie?
Directly behind the pupil
How is the lens of the eye held in place?
A ligament attached to the ciliary muscle
When is the ciliary muscle relaxed causing the lense to be almost flat,
When we look at far away objects
When the ciliary muscle contracts and causes curvature of the lens by pulling the choroid coat toward the lens, what distance are you looking
Near sighted
Presbyopia
Old sightedness or loosing ones ability to see up close.
Cataracts
Lens becomes hard, loses transparency, and becomes milky in color. This is caused by long term exposure to ultraviolet radiation.
Inner most layer of the eyeball
Retina
Name of photoreceptors cells in the retina
Rods and cones
Receptors of night vision
Rods
Receptors for daytime vision
Cones
Three types of cones are sensitive to what colors
Red, green, and blue
Yellowish area near the center of the retina
Macula lutea
Fovea centralis
A small depression surrounded by the macula lutea which contains the greates amount of cones in the retina
Name of the watery fluid in front of the lens
Aqueous humor
Name of the jellylike fluid behind the lens
Vitreous humor
When does glaucoma occur?
When the aqueous humor is blocked for any reason and the internal pressure of the eye can lead to damage and possible blindness
Process of refraction
Occurs as light passes through the cornea, the aqueous humor, the lens, and the vitreous humor on the way to the retina
Blind spot is know as the
Optic disc
Why is the optic disc a blind spot?
No rods or cones are present where the optic nerve fiber exits
Where is the visual cortex
Occipital lobe
Nearsightedness is also referred to as?
Myopia
Farsightedness is already referred to as
Hyperopia
