Vision

Question 1

Photo stimuli are electromagnetic waves between and ___ and ___ nm long

Answer 1

400 and 750

Question 2

What part of the eye regulates the amount of light that comes into the eye?

Answer 2

Pupil

Question 3

What controls the diameter of the pupil besides light?

Answer 3

Muscles in the iris

Question 4

When light enters the eye the pupil dilates, what is another name for this?

Answer 4

Mydriasis

Question 5

When the pupil constricts, what is the other name for it?

Answer 5

Mioisis

Question 6

What makes up the optic apparatus of the eye?

Answer 6

Lens + Cornea

Question 7

What determines the curvature of the lens?

Answer 7

Zonules + Ciliary muscles

Question 8

What region of the eye is the fovea found in?

Answer 8

Macula

Question 9

What is the inner cellular layer of the eye?

Answer 9

Retina

Question 10

What kind of fluids is found in front of the lens?

Answer 10

Aqueous humor

Question 11

What kind of fluids is found behind the lens?

Answer 11

Vitreous humor

Question 12

Aqueous humor is continuously secreted by the _____ ______, while the vitreous humor is a stable ______ mass

Answer 12

ciliary process

gelatinous

Question 13

Where specifically does the aqueous humor secrete between in the ciliary process?

Answer 13

Between the lens and iris (posterior chamber) thens through pupil into the space between iris and cornea (anterior chamber)

Question 14

What kind of nutrients does the aqueous humor provide to the lens and cornea?

Answer 14

Glucose

Question 15

Aqueous humor exits the eye through the ______ meshwork and ______ canal then drains into the ocular veins. Exits the eye through the _______ outflow pathway

Answer 15

trabecular

Schlemm’s

Uveoscleral

Question 16

Intraocular pressure is maintained within the normal range of….?

Answer 16

15mmHg (+/-3mmHg)

Question 17

High intraocular pressure causes what?

Answer 17

Glaucoma

Question 18

How do you treat high intraocular pressure?

Answer 18

Increase aqueous humor drainage.

Use Latanoprost (prostaglandin-like)

Question 19

What recycles the visual pigment molecules that are degraded using phototransduction?

Answer 19

Retina

Question 20

What is the outermost layer of epithelial cells of the eye?

Answer 20

Non-neuronal retina (retinal pigment layer)

Question 21

Of the retina, the outer segment faces the retinal pigment epithelium and has membrane folds called…? What does it contain?

Answer 21

disks

Rhodopsin

Question 22

What does rhodopsin have?

Answer 22

Protein opsin and retinal (vitamin A derivatives)

Question 23

Rods are (sensitive/not sensitive) to light and allow objects to be seen in (low/high) light intensity

Answer 23

sensitive

low

Question 24

Cones are (sensitive/not sensitive) to light and allow objects to be seen in (low/high) light intensity

Answer 24

not sensitive

high

Question 25

Highest density of cones are found in ....?

Answer 25

fovea

Question 26

What are the three types of cone photoreceptors?

Answer 26

Blue (Short) Green (Medium) Red (Long)

Question 27

In the dark, photoreceptors are depolarizing because...?

Answer 27

cGMP activates nonselective cation channels to open (Na+ influx), which causes release of glutamate

Question 28

In the light, retina absorbs the photons and causes what?

Answer 28

11-cis-retinal to all trans retinal (conformational change in opsin and rhodopsin is activated). Opsin is associated w/ GTP binding protein called transducin

Question 29

In the light, activation of transducin results in what?

Answer 29

Activation of PDE which degrades cGMP to 5'-GMP. The decrease in cGMP leads to closure of CNG channels

Question 30

When light energy is converted into a receptor potential, receptor potential for rods and cones are (depolarizing/hyperpolarizing)

Answer 30

hyperpolarizing

Question 31

In the light, closure of Na+ channels = ??? = reduction of ???? released

Answer 31

hyperpolarization glutamate

Question 32

Visual signals are transmitted into the superior portions of the ____ lobe and _____ posterior portions of the _____ lobe

Answer 32

occiptal parietal

Question 33

Visual signals representing color are transmitted mainly into the ______ visual cortex of the occipital lobe for further processing and interpretation

Answer 33

secondary

Question 34

What degrades cGMP to 5'GMP?

Answer 34

PDE

Question 35

The decrease in cGMP leads to closure of what?

Answer 35

CNG channels

Question 36

What activates PDE enzymes to be released?

Answer 36

Activation of transducin

Question 37

What activates the release of transducin?

Answer 37

Rhodopsin activating