Vision

Question 1

sclera

Answer 1

stiff, outer portion of the eye that helps it maintain its shape and give it its white color

Question 2

cornea

Answer 2

the transparent surface in front of the iris and pupil that allows light to pass through and helps with focusing

Question 3

conjunctiva

Answer 3

a clear membrane that covers much of the front of the eye for protection and moisturizing purposes

Question 4

aqueous humor

Answer 4

a clear fluid that supports the lens and fills the space between the lens and the cornea (front)

Question 5

lens

Answer 5

structure that sits behind the iris and focuses light on the retina

Question 6

biconvex lens

Answer 6

type of lens that curves out on both sides

found in the human eye

Question 7

ciliary bodies

Answer 7

structures that connect the iris to the choroid and control the shape of the lens through relaxing or contracting muscles

Question 8

ciliary muscles

Answer 8

circular smooth muscle that relaxes or contracts to control the shape of the lens in order to focus

Question 9

suspensory ligaments

Answer 9

fibrous membrane that attaches the ciliary body to the lens

Question 10

iris

Answer 10

structure at the front of the eye that contracts and expands to control the amount of light passing through

Question 11

pupil

Answer 11

a hole that varies in size with the contraction or relaxation of the iris

Question 12

vitreous humor

Answer 12

jelly-like substance that fills up the interior of the eye to give it structure (found behind the lens)

Question 13

retina

Answer 13

light-sensitive structure situated in the back of the eye that contains photoreceptors and sends signals to the brain via the optic nerve

Question 14

photoreceptors

Answer 14

type of nerve that can sense light and convert it into a neural response

Question 15

rods

Answer 15

most common type of photoreceptor

very sensitive to light and mostly located around the periphery of the retina

Question 16

cones

Answer 16

type of photoreceptor that is sensitive to color and is concentrated around the fovea

Question 17

choroid

Answer 17

black pigmented and highly vasculated structure found immediately behind the retina to supply it with nutrients

Question 18

fovea

Answer 18

indent within the retina that contains many cones in order to increase visual acuity for the object in focus

Question 19

macula

Answer 19

structure within the retina that includes the wider area around the fovea

Question 20

optic nerve

Answer 20

cranial nerve that sends signals from the photoreceptors of the retina to the brain

Question 21

blind spot

Answer 21

part of the retina that contains no photoreceptors

where the optic nerve enters the retina

Question 22

visible light

Answer 22

electromagnetic wave that can range in frequency from 400-700 nm

Question 23

phototransduction cascade

Answer 23

molecular steps of turning off a rod in the presence of light in order to transmit a signal
includes rhodopsin, phototopsin, bipolar cell, retinal ganglion cell

Question 24

rhodopsin

Answer 24

protein found in rod cells that responds to the change in shape of retinal (light sensitive molecule) when light is present through a conformational change and release of a subunit

Question 25

retinal

Answer 25

light sensitive molecule bound to rhodopsin that changes conformation when light is present and causes the conformational change in rhodopsin

Question 26

transducin

Answer 26

a G-protein that responds to the change in shape of rhodopsin by activating cGMP phosphodiesterase

Question 27

cGMP ophosphodiesterase

Answer 27

enzyme that converts cGMP into GMP

Question 28

photopsin

Answer 28

protein that functions in the same way as rhodopsin but is found in cones rather than rods

Question 29

bipolar cell

Answer 29

type of cell that receives signals from rods and transmits it to the retinal ganglion cells

Question 30

on-center bipolar cell

Answer 30

synapse with rod cells and are activated in the presence of light due to the deactivation of rod cells

Question 31

off-center bipolar cell

Answer 31

synapse with rod cells and are deactivated in the presence of light due to the activation of rod cells

Question 32

retinal ganglion cell

Answer 32

type of cell that receives signal from the bipolar cell and passes the signal onto the optic nerve

Question 33

visual processing

Answer 33

method by which the body is able to convert information from photoreceptors into an image we can make sense of

Question 34

nasal side of the eye

Answer 34

medial portion of the eye

Question 35

temporal side of the eye

Answer 35

lateral portion of the eye

Question 36

optic chiasm

Answer 36

point at which the optic nerves from each eye converge and information from the nasal side of the eye crosses over

Question 37

feature detection

Answer 37

concept that describes how different cells in the eye perceive specific aspects of complex stimuli

Question 38

parallel processing

Answer 38

method by which the brain is able to use the signals from many different cell types to allow us to see color, form, and motion all at once

Question 39

trichromatic theory

Answer 39

idea that there are three different types of photoreceptors that detect different wavelengths of light
one responds to short wavelengths (blue), one to medium wavelengths (red), and one to long wavelengths (red)

Question 40

Parvo pathway

Answer 40

group of specialized cells that are important for seeing with high spatial resolution and for seeing color
these cells have low temporal resolution

Question 41

spatial resolution

Answer 41

how clear the perception of an image is when it is not moving

Question 42

temporal resolution

Answer 42

how clear the perception of an image is when it is moving

Question 43

Magno pathway

Answer 43

a group of specialized cells that are important for seeing with high temporal resolution
these cells have low spatial resolution and do not detect color