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22 Cards in this Set
- Front
- Back
white outer fibrous layer of the eye |
sclera |
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middle vascular layer of the eye |
choroid |
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the two humours of the eye and their location |
aqueous: surrounding the lens in the anterior cavity
vitreous: in the posterior cavity |
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what is the inner nervous layer of the eye |
retina |
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what is the fovea centralis? |
area of the retina that has only cone cells |
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what is the optic disk? |
area where nerves become the optic nerve -- produce a blind spot |
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what is myopia? |
nearsightedness -- eyeball is too long for proper focusing |
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what is hyperopia? |
far-sightedness produced by a shorter eyeball |
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what is presbyopia? |
farsightedness due to age |
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what is astigmatism? |
defect in the curvature of the cornea or lens -- some portions of an image are blurred |
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what are the other eye disorders? |
- cataract: cloudyness of the lens - floaters: small moving specks in the field of vision appear due to clumps of gel or deposits of crystal-like substances in vitreous humour - glaucoma: the rate of aqueous humour production exceeds the rate at which it drains - colour blindness: particular type of cone is deficient in number or lacking |
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what are the types of colour blindness |
- protanopic: defective perception of red -- confuses red with green - deuteranopic: insensitivigty to green -- can't see red or distinguish green and purplish-red - tritanopic: confusion between blue with green and yellow with violet |
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how is hearing recepted in the cochlea? |
highest frequency waves recepted at base of cochlea and lowest frequency at tip |
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what are the types of hearing loss? |
- conductive deafness: interference with vibrations to the inner ear -- may be due to accumulated wax or objects - sensorineural deafness: damage to the cochlea or auditory nerve - presbycusis: loss of ability to hear high frequency waves |
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what are the vestibular disorders? |
- motion sickness: when both rotational and linear inputs from vestibular system unpredictable - vertigo: unexpected illusion of movement or of one's surroundings - meniere's disease: dizziness due to unbalanced input from both ears |
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what are the types of touch receptors? |
- sensory nerve fibres - meissner's corpuscles: sense motion of objects barely in contact with skin - pacinian corpuscles: deeper in skin and sense pressure |
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what is sensitivity and acuity? |
sensitivity: ability to dinstinguish differences in pressure acuity: ability to distinguish between to points of equal pressure |
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what is a motor unit? |
one motor neuron and all the muscle fibers it innervates |
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what are the types of muscle contraction |
isotonic: muscle shortens during contraction isometric: muscle contracts but does not shorten |
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What is the term for far-sightedness with age |
presbyopia |
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what is far sightedness with shorter eyeball |
hyperopia |
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what is near-sightedness due to longer eyeball |
myopia |