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Optics
Basic Neuro: Optics
59
Medical
Professional
03/21/2012

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Cards

Term
bending of light when it encounters a different medium
Definition
Refraction
Term
distance beyond a convex lens where rays converge on a common focal point
Definition
Focal length
Term
measure of the refractive power of a lens: reciprocal of the focal length
Definition
Diopter
Term
convex lenses have + or - diopters?
Definition
+
Term
concave lenses have + or - diopters?
Definition
-
Term
the fatter the convex lens the shorter or longer the focal length?
Definition
shorter (more refractory power)
Term
the thinner/flatter the convex lens the shorter or longer the focal length?
Definition
longer (less refractory power)
Term
convex lenses generate inverted or upside up images?
Definition
inverted
Term
most of the refractive power comes from the?
Definition
cornea
Term
we change the shape of the _______ to increase refractive power.
Definition
cornea
Term
1/3 of the refractive power comes from the ________
Definition
cornea
Term
the lens increases or decreases curvature to accommodate for near vision?
Definition
increases
Term
when the lens is fattened to focus on something in the near visual field
Definition
accommodation
Term
contraction of the ________ muscles causes less tension on the ligaments and the lense increases its curvature and refraction
Definition
ciliary mm
Term
nonaccommadation of the lens
Definition
Presbyopia
Term
older folks get _______ due to dec elasticity of the lens
Definition
Presbyopia
Term
tx for presbyopia
Definition
bifocals / convex lens
Term
Normal vision
Definition
Emmetropia
Term
farsighted, focal point behind the retina, tx with convex lens
Definition
Hypertropia
Term
nearsighted, focal point in front of the retina, tx with concave lens (biconcave lens)
Definition
Myopia
Term
so reading glasses have convex or concave lenses?
Definition
convex
Term
reading glasses have + or - diopters?
Definition
+
Term
cannot focus on the horizontal and vertical place at the same time, can only focus on one at a time, it is due to a non uniform curvature of the lens, tx with cylindric lens
Definition
Astigmatism
Term
cylindric lens tx for?
Definition
Astigmatism
Term
biconcave lens is tx for?
Definition
Myopia
Term
convex lens is tx for
Definition
Hypertropia / Presbyopia
Term
color vision, high acuity
Definition
cones
Term
black and white, dim light
Definition
rods
Term
Multiple Rods or cones converge on one bipolar cell allowing high sensitivity and low acuity to light
Definition
Rods
Term
Few Rods or cones converge on one bipolar cell allowing low sensitivity and high acuity to light
Definition
Cones
Term
the majority of cones are located in the
Definition
fovea
Term
the highest acuity to light is found in the
Definition
fovea
Term
parting of the seas of ganglion / bipolar cells so that light is not bent and the highest visual acuity may be achieved
Definition
Fovea
Term
Rods or cones must always synapse on an amacrine cell which then synapses on a bipolar cell?
Definition
Rods
Term
Rods or cones can synapse on a biopolar cell without an amacrine cell intermediate
Definition
Cones
Term
I Never Give In (2x) Or (3x) Let People laugh at Ch-you (see slide in corso ppt)
Definition
Inner limiting membrane
Neuronal fibers
Ganglion cell layer
Inner plexiform layer
Inner Nuclear layer
Outer plexiform layer
Outer neuronal layer
Outer limiting membrane
Layer of Rods and Cones
Pigmented Epithelium
Choroid
Term
contains melanin to prevent light from reflecting in the eye ball, stores vit A, degrades old photoreceptor discs
regenerates photo pigment molecules
Definition
Pigmented epithelium
Term
have no melanin, dec absorption of light causing dec accuity - light bounces around in the eye instead of being absorbed and more rods and cones are activated
Definition
Albinism
Term
has an opsin part and a retinal part
Definition
Rhodopsin
Term
_____ causes 11-cis-retinal to convert to all-trans form
Definition
light
Term
form of retinal that can bind to opsin
Definition
11-cis-retinal
Term
_________ uses vit A to recycle all-trans retinal and convert it back to 11-cis-retinal
Definition
Pigmented epithelium
Term
process of 11-cis-retinal to all trans retinal conversion
Definition
photoisomerization
Term
vit A def - causes _______ bc all trans retinal cannot be recycled back to 11 cis retinal
Definition
night blindness
Term
photoisomerization causes an intermediate (_____________) to form which activates a G protein called ___________, which activates a phosphodiesterase which dec levels of ______, which causes closure of Na+ channels which causes the cell to ___________
Definition
metarhodopsin, transducin, cGMP, hyperpolarize
Term
hyperpolarization causes a __________ in the amt of either an excitatory or inhibitory NT release from the rod or cone
Definition
decrease
Term
When in the bright light much of the retinal will be converted to retinol:
Definition
reduced sensitivity to light
Term
When in the dark for a long time the rhodopsin is regenerated and in high supply :
Definition
increased sensitivity to light
Term
photoactive chemicals in cones
Definition
photopsin
Term
equal stim of all three color pigments
Definition
white light
Term
loss of green cones
Definition
deuteranopia
Term
loss of red cones
Definition
protanopia
Term
can see all cones
Definition
trichromatic
Term
Rods and cones secrete _______ at bipolar cell synapses
Definition
glutamate
Term
only _____ cells actually generate an action potential in the retina, all other cells transmit electrical changes thru the cytoplasm
Definition
ganglion cells
Term
always inhibitory, patterns and acuity, lateral inhibition
Definition
horizontal cells
Term
many types, analyze visual info before leaving the retina, increase contrast
Definition
amacrine cells
Term
on center
Definition
white (depolarized bipolar) on black (hyperpolarized bipolar)
Term
off center
Definition
black (hyperpolarized bipolar) on white (depolarized bipolar)
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