Sense Of Vision

Front 1

How many layers does the eyeball have and what are they?

Back 1

1 sclera
2 choroid
3 Retina

Front 2

The majority of the window of the eye is responsible for what? What part of the eye is this?

Back 2

focusing of the light (transparent part) cornea

Front 3

The part of the eye made up of transparent collagen fibers is responsible for what?

Back 3

The majority of the focusing of the light

Front 4

The layer of the eye that has an extensive blood supply serves what funciton?

Back 4

(choroid) absorbs stray light rays that photopigments have not absorbed

Front 5

The layer of reflective tissue within the choroid of some animals is called what? What does it do?

Back 5

(choroid) Tapetum lucidum allows greater sensitivity in dark environments

Front 6

What does the layer that absorbs stray light rays become toward the front?

Back 6

iris.

Front 7

What does the front of the choroid layer do?

Back 7

regulates the size of the pupil

Front 8

What juice could you place in the front part of the choroid layer to keep it contracted? How does it do this?

Back 8

Belladonna (deadly nightshade), produces drugs that interfere with synapses that release acetylcholine (anticholinergic) INHIBITORY EFFECT greatest on parasympathetic nerves that normally cause the iris to contract, Causes the pupils to dilate

Front 9

Nocturnal animals have what type of tissue that bounces around inside the eyeball? What does this enable the animal to do?

Back 9

refracted tissue (tapetum lucidum) causes the eye to be more sensitive but not great clarity

Front 10

what are 2 examples of what belladonna produces that pupils to dilate?

Back 10

atropine and scopolamine

Front 11

Why does the iris contract and dilate?

Back 11

To compensate for changes in light intensity

Front 12

What type of light will cause the pigmented portion of the eye to contract?

Back 12

White light (iris)

Front 13

What causes the photic sneeze reflex?

Back 13

X-wiring of the nerves of roof of nose and eyes: genetic/inherited condition

Front 14

What are the 2 biometric identifiers?

Back 14

Retina and iral scan

Front 15

Heavily pigmented eyes are usually what color? Light?

Back 15

Brown, blue or green

Front 16

What are the retinal and iral scans called?

Back 16

Biometric identifiers

Front 17

What is the function of the portion of the eye that thickens and is located just behind the iris? What does it contain?

Back 17

(Ciliary body): contains the ciliary muscle which contros the shape of the lens for near and far vision.

Front 18

What is supported by suspensory ligaments and attached to teh part of the eye located just behind the iris? What is its function?

Back 18

The lens, carry out minor focusing of incoming light

Front 19

What divides the eye into 2 compartments? What do these 2 compartments contain

Back 19

The lens anterior compartment: fileld with aqueous humor (produced each day)

Front 20

What disease is caused by blockage of ducts that drain the anterior compartment? What would this anterior compartment be part of? what can it lead to?

Back 20

glaucoma, aqueous humor builds up-->pressure compresses the arteries that serve the nerve fibers of the retina, where photoreceptors are located. Nerve fibers die due to lack of nutrients, and the person becomes blind.

Front 21

How can you detect for the disease that drains the aqueous humor of the eye?

Back 21

blowing a puff of air at the cornea to measure its tightness

Front 22

What is the lens composed of?

Back 22

contains flexible crystaline protein

Front 23

What muscle is responsible for changing the shape of the lens?

Back 23

Ciliary muscle

Front 24

What type of fluid is in the anterior compartment of the lens? Posterior?

Back 24

ant: aqueous humor
post: vitreous humor

Front 25

The layer of the eye located in the posterior compartment is filled with what gelatinous material? What does it do?

Back 25

(retina) filled with vitreous humor that holds the retina in place and supports the lens

Front 26

What does the retina contain?

Back 26

photoreceptors rod cells and cone cells

Front 27

the unique patter of BV's in the choroid and retian can also be used by the government for what?

Back 27

biometric identifier

Front 28

The pattern of BV's in what 2 layers of the eye can be used by the govenrment as a biometric identifier?

Back 28

retina and choroid

Front 29

What controls the shape of the lens for near and far vision?

Back 29

ciliary body that contains the ciliary muscle

Front 30

Where does the aqueous humor drain into?

Back 30

The venous system (aqueous humor is in the anterior portion of the eye_)

Front 31

The portion of the eye that contains the vitreous humor also contains cells that are sensivite to light, how do these cells get overwhelmed by bright light?

Back 31

rod cells, do not have color therefore at night or in a darkened room, we see only shades of gray.

Front 32

What cells in compartment that contains the vitreous humor of what anatomical structure is responsible for what? What is the anatomical structure? What type of light do they need?

Back 32

retina, responsible for distinguishing colors, bright light

Front 33

The part of the eye where vision is most acute has what type of densely packed cells?

Back 33

(in the fovea centralis) cones

Front 34

What forms the optic nerve? From where?

Back 34

Sensory fibers from the retina

Front 35

CS: What was causing Mike's vision loss? How will they treat it?

Back 35

detached retina, fine lasers to heat samll areas all over the retina to reattach the nerve part of the retina to the BV's behind it.

Front 36

CS: If mike had had a heart attack, what would show up in his blood?

Back 36

proteins from his heart cells.

Front 37

what focuses vision to the retina? What assists it?

Back 37

conea: lens and the humors

Front 38

The image produced by the cornea is much smaller than the object, why?

Back 38

The light rays are bent (refracted) when they are brought into focus

Front 39

The portion of the eye that flips an object upside down and backwards also has a function that allows the image to focus on the retina, what is this funciton? What does it occur for?

Back 39

(Lens), VISUAL ACCOMODATION occurs for close vision

Front 40

What will the portion of the eye that is responsible for flipping an object upside down and backwards do when viewing a distant object? What is the purpose of this part of the eye?

Back 40

(lens) flattens out, bend light.

Front 41

The portion of the eye that flattens when viewing a distant object is acted upon by what muscle?

Back 41

(lens) ciliary muscle (it's actually relaxed though) NICE QUESTION!

Front 42

What part of the eye reacts when viewing a near object, what does the muscle associated with this portion of the eye do?

Back 42

ciliary muscle contracts and the suspensory ligaments release their tension and the lens rounds up.

Front 43

What does the lens round up due to?

Back 43

natural elasticity.

Front 44

What allows the image to be focused on the retina?

Back 44

contraction or relaxation of the ciliary muslce

Front 45

What happens to the portion of the eye repsonsible for flipping an object upside down and backwards if viewing a close object for an extended period of time? Why?

Back 45

eyestrain: thick lens (more divurgent light to bring to retina)

Front 46

What if you lost some elasticity of the lens, what is the condition associated with it?

Back 46

You'd have trouble seeing things close up PRESBYOPIA

Front 47

what condition is often in apparent after the age of 40 that affects the ability of the lens to round up or not? Why would this happen? What would solve the problem?

Back 47

presbyopia, the elastic recoil of the lens loses its elasticity, glasses with a magnifying lens or bifocal lenses may be necessary for those

Front 48

When does the pathway for vision begin?

Back 48

once light has been focused on the photoreceptors in the retina

Front 49

what occurs in the area of the eye that images are focused on where nerve impulses begin before the optic nerve transmits them to the brain?

Back 49

integration

Front 50

The visual pigment in the part of the eye that only sees black and white contains a visual pigment called what?

Back 50

(rods) Rhodopsin

Front 51

What is the complex molecule that is in the part of the eye that only sees black and white made up of?

Back 51

(RODS, RHODOPSIN) made up of protein opsin and a light-absorbing molecule called retinal.

Front 52

This complex molecule is made up of 2 proteins that is in the portion of the eye that only sees black and white. which component of this molecule is a derivative of vitamin A? what is the other component of this molecule?

Back 52

Rhodopsin, Rods, retinal, opsin

Front 53

What happens immediately after a rod absorbs light?

Back 53

Rhodopsin splits into opsin and retinal

Front 54

How does vitamin A improve night vision?

Back 54

It allows you to synthesize Rhodopsin more readily.

Front 55

What are thrashed in bright sunlight making it so you can't see in the dark? What has to happen so you can see agian?

Back 55

rods are thrashed in bright sunlight, rhodopsin has to be regenerated again.

Front 56

Red light will not cause what to happen to the function of the photoreceptors?

Back 56

will not break down rhodopsin,

Front 57

Why would you look through red light while star gazing/

Back 57

exposing the rods to red light will not break down rhodopsin

Front 58

When does the visual pathway to the brain begin?

Back 58

once light has been focused on the photoreceptors in the retina

Front 59

the light sensitive cells of the retina have what in the peripheral portions and what in the middle? What is the middle portion called?

Back 59

Rods in teh peripheral
cones where light is mostly focused on the retina (fovea centralis)

Front 60

Which light sensitive cell is is suited to night vision?

Back 60

Rods

Front 61

What happens to the ion channels in the rod's plasma membrane once the Rhodopsin splits?

Back 61

They close

Front 62

The release of what type of transmitter molecules from the rod's synaptsic vesicles ceases and what happens after?

Back 62

inhibitory signals go to other neurons in the retina.

Front 63

Eating carrots will improve this portion of the eye and contribute to the regenration of rhodopsin after you leave the sunlight. What is this called?

Back 63

(rods)Dark-adaption period

Front 64

Where are there more rods and cones?

Back 64

more rods in teh peripheral portion of the retina more cones near where light is mostly focused on the retina

Front 65

Where is light mostly focsed on the portion of the located in the posterior compartment, which is filled with vitreous humor?

Back 65

fovea centralis

Front 66

sudden exposure to bright white light will destroy what? What will need to occur again once this happens?

Back 66

rhodopsin, "dark-adaptation period"

Front 67

The photoreceptor that is only responsible for seeing a shade of gray are plentiful everywhere except one place, what is that place?

Back 67

(rods) fovea centralis.\

Front 68

Why aren't you able to see satellites when you look straight at them?

Back 68

No rods in the middle, so if you stare straight at the satellite, it disappears in night vision, staring fixedly at an object in a dark environment will cause the rhodopsin to become exhausted and the object to disappear!

Front 69

What complex molecule made up of a protein and a molecule will become exhausted in a dark environment?

Back 69

Rhodopsin

Front 70

What happens to the molecule that has a deep purple pigment when staring fixedly at an object in a dark environment? What should you do?

Back 70

Rhodopsin exhausts and the image disappears, rotate your eyes!

Front 71

What does the photoreceptor capable of distinguishing color allow us to detect? Where are these photoreceptors located?

Back 71

The fine/ precise imagery of an object located in the fovea centralis

Front 72

The photoreceptors in the fovea centralis are only able to individual absorption patterns, what accounts for this?

Back 72

each pigment is made up of retinal and opsin, but there is a slight differnce in the opsin structure of each, which accounts for their individual absorption patterns.

Front 73

Why do we have cones for just the 3 pigments?

Back 73

The 3 projected primary lights are RB and G, These 3 can project all colors of rainbow.

Front 74

What stimulates various combinations of cones?

Back 74

in-between shades of color

Front 75

How can cones detect any color?

Back 75

The 3 types of cones represent the 3 primary colored lights, and the perception of color is determined by our brain.

Front 76

what determines the eventual perception of color?

Back 76

the brain

Front 77

What are the 3 layers of neurons the retina has?

Back 77

deepest layer rods and cones
middle layer bipolar cells
innermost layer: contains ganglion cells whose snesory fibers become the optic nerve.

Front 78

The portion of the eye that is located in the posterior compartment filled with vitreious humor has 3 layers of the nervous tissue that transmits impulses, what is this tissue and what is the innermost layer contain?

Back 78

ganglion cells, whose sensory fibers become the optic nerve

Front 79

The portion that light hits after passing through the vitreous humor is contains what? What do these structures become?

Back 79

ganglion cells whose sensory fibers become the optic nerve.

Front 80

Only 2 types of cells are sensitive to light, what are they? What do they connect with (what's another word for conenct/?

Back 80

rod and cone cells that synapse with the bipolar cells, which in turn synapse with ganglion cells whose axons become the optic nerve.

Front 81

What does the layer closest to the choroid contain?

Back 81

(deepest layer) rod cells and cone cells

Front 82

Which layer is only sensitive to light?

Back 82

the deepst layer that contains rods and cones

Front 83

The ganglion cells synapse with what cells?

Back 83

bipolar cells

Front 84

What becomes the optic nerve?

Back 84

The syanpse with ganglion cells whose axons become the optic nerve.

Front 85

What layer of the retina contains the photoreceptors? What layer is it closest to?

Back 85

The deepest layer, rod cells and cone cells, closest to the choroid

Front 86

The layer that contains the photoreceptors contains more cells than what type of cells? Why?

Back 86

Many more rod cells than ganglion cells

Front 87

The photoreceptor most numerous in the eye, do not generate as precise an image, why is this?

Back 87

as many as 150 rods may activate the same ganglion cell whose sensory fibers become the optic nerve.

Front 88

What explains why the photoreceptors located in the center of the eye provide us with a sharper, more detailed image?

Back 88

Some cone cells (located in the fovea centralis) activate only one ganglion cell

Front 89

What occurs as signals pass from the layer that light hits after passing through the vitreous humor to the middle layer? Where does this process occur again?

Back 89

ganglion cells to bipolar cells: integration occurs, considerable processing occurs in the retina before ganglion cells generate nerve impulses. additional integration occurs in the visual cortex

Front 90

What is another name for the blind spot?

Back 90

optic disc

Front 91

Why do you have a blind spot?

Back 91

there are no rods or cones where the optic nerve exits the retina

Front 92

why do you still have complete vision when you have a place in the eye that has no photoreceptors?

Back 92

(blind spot/optic disc; rods cones), The two eyes together provide complete vision because the blind spot for the right eey is not the same as the blind spot for the left eey.

Front 93

To reach the visual cortex, what crosses?

Back 93

optic nerves, optic chiasma

Front 94

Where does the optic tract sweep around? why is this importnat?

Back 94

around the hypothalamus, most fibers synapse with nuerons in nuclei (masses of neuron cell bodies) within the thalamus

Front 95

The place that the optic tracts sweep around the hypothalamus and synapse with neurons in nuclei is called what? What do htey form? What do they do

Back 95

thalamic nuclei form optic radiations tha ttake nerve impulses to the visual cortex w/in occipital lobe

Front 96

What take nerve impulses to the occipital lobe, what is the place in the occipital lobe that these things go?

Back 96

optic radiations, visual cortex

Front 97

What causes the image to split?

Back 97

R visual cortex receives information originally carried by the right optic tract, and the L visual cortex receives info originally carried by the L optic tract.

Front 98

How is good depth perception mainatined?

Back 98

The R and L visual cortices communicate with each other.

Front 99

What causes color blindness and how does it occur? What is the most common mutation? If the eye lacks the photoreceptor that responds to red wavelenghts, what colors are accentuated?

Back 99

genetic mutation, only one type of cone is defective or defiicient in #. The most common mutation is the inability to see the colors red and green. Green and vice versa

Front 100

How does the world look to our retina?

Back 100

upside down and backwards

Front 101

Why does a person have to stand 20 feet from an eye chart?

Back 101

(Snellen Eye Chart) so accommodation does not influence the test.

Front 102

What is accomodation? What controls it?

Back 102

The lens changes its shape to bring the image to focus on the retina. Ciliary muscle

Front 103

If the ciliary muscle is relaxed, how close would the object you be viewing? What would be the shape of the lens? Why?

Back 103

distant object, causing the suspensory ligaments attached to the cilary body to be taut and the lens remains relatively flat.

Front 104

What 2 devices act on the lens?

Back 104

ciliary muscle, suspensory ligamnets

Front 105

If the portion of the eye attached by suspensory ligaments and divided into 2 compartments were uneven, what would this condition be called?

Back 105

astigmatism

Front 106

how does looking through a pinhole help to correct your vision?

Back 106

by eliminating the peripheral rays of light that contribute to a fuzzy image and only leaving the central rays to hit the fovea.

Front 107

What does pulling at the corner of your eyelid do to help you see more clearly? What type of individual would that help?

Back 107

flattens the cornea and helps the myopic individual see more clearly

Front 108

What is the process called when you use a laser after an outer flap of cornea is cut aside?

Back 108

corneal sculpting

Front 109

What results when the crystalline proteins of the lens becomes denatured?

Back 109

Cataracts

Front 110

What condition of the eye would occur from poor nutrition or excessive exposure to UV light?

Back 110

a cataract

Front 111

What is another name for small bits of protein or cells floating in the vitreous humor or behind the lens in the posterior cavity?

Back 111

floaters (muscae volitantes)

Front 112

CS: What is it about in the section of vision?

Back 112

Mike has diabetes and goes blind in one eye, ophthalmologist sees that the retina is detached. Surgically they heat small areas all over his retina and reattach the nerve part of the retina to BV's behind it.

Front 113

CS: What was the surgery done for MIke?

Back 113

fine lasers to heat small areas all over the retina to reattach the nerve part of the retina to the BV's

Front 114

CS: How could a diabetic go blind?

Back 114

high blood pressure could cause bv damage to the eye and not provide the nourishment the retinal cells need to continue to function

Front 115

CS: Why is detaching the retina bad?

Back 115

the choroid layer behind it is what nourishes the cells of the retina (rods and cones)

Front 116

What bends the light rays hitting the retina?

Back 116

cornea