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68 Cards in this Set
- Front
- Back
The innermost layer (nervous tissue) of the eye
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Retina
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Photoreceptor cells called _____ and _____ compose the visual receptors (fro the optic nerve) of the retina.
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Rods
Cones |
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What do rods and cones contain?
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Photopigments
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How many different photopigments are there?
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4
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What are the constituents of a photopigment?
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Opsin (protein) attached to retinal (chromophore molecule)
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What differs form pigment to pigment and confers specific light-sensitive properties on each photopigment.
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Opsins
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What is retinal produced from?
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Vitamin A
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What is the photopigment of Rods?
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rhodopsin
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What photoreceptors indicate different degrees of brightness and is characterized by a relative lack of color discrimination.
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Rods
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Where are rods located in abundance?
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Periphery of the retina
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What photoreceptors are responsible for color vision?
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Cones
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What are the three different types of cones?
What does each contain? |
Red, Green, Blue
Diff. photopigment attuned to certain wavelength |
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Where are cones primarily concentrated?
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Center of retina (Fovea)
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What is Synthesized during dark adaptation or night vision?
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Rhodopsin from rods
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What are the most abundant photoreceptors, that have higher sensitivity, and lower acuity?
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Rods
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The crystal clear dome that covers the front of the eye.
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Cornea
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The majority _____ of the bending (refracting) of light rays is accomplished by the _____.
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70%
Cornea |
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The shape of the cornea _____ _____ _____.
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Does not change
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The crystaline structure which finishes focusing the light, and helps to fine-tune vision and is able to change shape to allow focus on near objects.
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Lens
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What is it called when the lens becomes cloudy?
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Cataract
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The opening in the middle of the iris.
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Pupil
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The part of the eye that gives it color. Functions like a shutter in a camera, allowing more or less light into the eye.
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Iris
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Thin layer of nerve tissue that senses light. This is analogous to the film in the camera.
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Retina
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The center of the retina that receives the focus of the object of regard.
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Fovea
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Why can images focused on the fovea be seen in greater detail?
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Nerve cells are more densely packed in this region
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The nerve that runs from the eyeball to the brain, carries information from the retina to the brain for interpretation
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Optic Nerve
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What fluid fills the anterior chamber of the eye?
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Aqueous humor
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What fluid fills the posterior segment of the eye?
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Vitreous humor
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What does a sound wave strike first in the ear?
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Tympanic membrane
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What is the path of sound wave transference?
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Tympanic membrane vibrates - membrane of oval window vibrates - perilymph/endolymph moves - Basilar membrane vibrate - Stimulation of hairs on organ of corti - CN stimulation
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Where is the perilymph located?
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Boney labyrinth of Cochlea
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Where is the endolymph located?
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Membranous labyrinth of Cochlea
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What are the external parts of the ear?
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Auricle
External auditory canal |
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What directs sound waves?
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Auricle (pinna)
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What contains hair and cerumen (brown earwax) and serves as a resonator
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External auditory canal (meatus)
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what are the parts of the middle ear?
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Auditory tube
Ossicles |
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Air-filled cavity in the temporal bone.
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Middle ear (tympanic cavity)
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What part of the ear equalizes pressure?
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Auditory tube
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What part of the ear links together to transmit sounds to the oval window?
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Ossicles (malleus, incus, stapes)
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What are the organs of the Inner Ear?
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Vestibule
Semicircular canals Cochlea |
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Where is the perilymph located?
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Boney labyrinth of Cochlea
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Where is the endolymph located?
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Membranous labyrinth of Cochlea
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What are the external parts of the ear?
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Auricle
External auditory canal |
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What directs sound waves?
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Auricle (pinna)
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What contains hair and cerumen (brown earwax) and serves as a resonator
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External auditory canal (meatus)
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what are the parts of the middle ear?
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Auditory tube
Ossicles |
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Air-filled cavity in the temporal bone.
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Middle ear (tympanic cavity)
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What part of the ear equalizes pressure?
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Auditory tube
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What part of the ear links together to transmit sounds to the oval window?
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Ossicles (malleus, incus, stapes)
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What are the organs of the Inner Ear?
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Vestibule
Semicircular canals Cochlea |
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What part of the ear is formed by the membranous labyrinth within a bony labyrinth?
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Inner Ear
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What part of the ear is associated with a sense of balance?
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Vestibule (saccule and Utricle)
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What part of the ear is concerned with equilibrium?
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Semicircular canals
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What is the portion of the ear responsible for hearing. The basic functional unit for hearing because it transforms fluid vibrations from sound waves into a nerve impulse.
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Cochlea
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What are the two membranes found in the cochlea?
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Vestibular and Basilar
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Constriciton of the pupil of the eye
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Miosis
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The prolonged abnormal dilation of the pupil of the eye induced by a drug or caused by a disease.
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Mydriasis
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What is the deficiency in which the eye is too long for the refractive power of the lens, and far objects are focused at a point _____ of the retina?
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Myopia (nearsightedness)
In Front |
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What are the causes of Myopia (nearsightedness)?
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Steep cornea
Longer than normal eye |
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What is used to treat Myopia?
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Concave lenses
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What is nearsightedness essentially?
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See well up close and struggles at a distance
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What deficiency occurs when light entering the eye focuses _____ the retina instead of directly on it?
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Hyperopia (farsightedness)
Behind |
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What causes hyperopia (farsightedness)?
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Flatter cornea
Shorter than normal eye |
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What is farsightedness essentially?
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See well far away, but have trouble seeing up close
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How is Hyperopia treated?
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Convex lenses
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What occurs when the curvature of the lens is not uniform and is corrected with _____ lenses?
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Astigmatism
Cylindrical |
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What is the inability of the eye to focus sharply on nearby objects, resulting from the loss of elasticity of the lens with advancing age?
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Presbyopia
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How is Presbyopia corrected?
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Bifocals
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