149 & 150 Special Sense: Vision Flashcards

1
Q

most of the refraction of light takes place in the

A

cornea

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2
Q

how is the aqueous humor formed

A

ciliary body secretes Na, which then pulls in water and Cl, other nutrients enter ia facilitated diffusion

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3
Q

what is the flow of aqueous humor

A

flows through pupil, angle of anterior chamber, Trabecular meshwork, canal of schlemm, aqeuous ceins

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4
Q

increased intraocular pressure leads to

A

glaucoma

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5
Q

if you hace a closed angle, when will you hae symptoms

A

in the dark, when the eyes try to dialate

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6
Q

what allows you to accomodate for far target

A

ciliary muscles relax, suspensory ligament contract

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7
Q

what muscle helps with ocular conergence

A

medial rectus

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8
Q

what is presbyopia

A

loss of accomodation of lens (seen with age)

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9
Q

what is cycloplegia

A

loss of accomodation due to loss of ciliary muscle (atropine)

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10
Q

Constriction _____ the angle of the anterior chamber

A

increases

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11
Q

what is the pathway for pupillary reflex

A

light, CN II, pretectal area, EDINGER_WESTPHAL NUCLEUS, CN III, ciliary ganglion, ciliary muscles, constrictor pupilae

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12
Q

what three things are in depth perception

A

size of object, moing parallax, steropsis

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13
Q

where is itamin A stored

A

pigmented layer

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14
Q

what is the light sensitie pigement in rods

A

rhodopsin

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15
Q

what is rhodopsin composed of

A

scotopsin and retinal

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16
Q

the unstimulated retinal is in _____ form

17
Q

what happens when retinal is conerted to all trans

A

no longer fits with scotopsin -> bathorrhodopsin -> decays into lumirhodospin-> metarhodopsin

18
Q

what conerts all trans retinal to cis

19
Q

unstimulated rods are _______

A

depolarized (Na influx through cGMP gated channels)

20
Q

upon stimulation with light, rods become

A

hyperpolarized

21
Q

destabilization of rhodopsin actiates

A

transducin

22
Q

what does transducin actiate

A

cGMP phosphodiesterase

23
Q

how can viagra cause blindness

A

it inhibits phospodiesterase, resulting in the cells staying depolarized and not reacting to light

24
Q

what inactates metarhodopsin II

A

rhodopsin kinase

25
Rods dont see
Red
26
when is pigment converted to vitamin A
bright light
27
what role does calcium play in light adaptation
indirectly regualtes cGMP dependent channels
28
which cells sharpen retinal image
biolar
29
which cells provide contrast
horizontal
30
which cells control light senstitivity
amacrine
31
the output of horizontal cells is always
inhibitory
32
which cells are responsible for circadia rhythm
ganglion cells
33
are p or m cells sensitive to color
P (less sensitive overall and does fine details)
34
what nucleus of hypothalamus controls circadian rhytm
suprachiasmatic nucleus
35
what area of the thalamus does reflex movement of the eye
pretectal
36
what area of the brain does rapid directional movement of both eyes
superior colliculi
37
lateral geniculate nuclei sends fibers to
EW