VISION B

Question 1

130 million _________ in retina transform light
intensity/color patterns into chemical and electrical signals which trigger activity of retinal cells.
• Information of 130 million photoreceptors is compressed to 1 million highly specialized ________
• 1 million ganglion cells in the retina form the optic nerve and transmit visual information to the ______

Answer 1

Photoreceptors
Ganglion cells
Visual cortex

Question 2

____ causes blind spot - our brain fills in for it

Answer 2

Optic disc

Question 3

___________:
-Color specific and high acuity
-Are concentrated in the fovea

Answer 3

Cone photoreceptors

Question 4

_________
-No Color specificity, low acuity but high sensitivity
-rods are present in the peripheral retina

Answer 4

Rod photoreceptors

Question 5

Color & high acuity = ___ photoreceptors
Colourless but sensitive = ___ photoreceptors

Answer 5

Cone
Rod

Question 6

What are the 3 classes of cones ?

Answer 6

S cones
M cones
L cones

Question 7

_____ cones = short wavelength sensitive

Answer 7

S (short )

Question 8

____ cones = long wave length sensitive

Answer 8

L (long)

Question 9

___ cones= middle wavelength sensitive

Answer 9

M (middle)

Question 10

What are they 3 Color vision deficiencies ?

Answer 10

Monochromats
Dichromats
Trichromats

Question 11

______- totally colour blind with one cone pathway plus rod pathway

Answer 11

Monochromats

Question 12

________- a cone photopigment missing thus has only two cone channels

Answer 12

Dichromats

Question 13

______- all three cone photopigments with one cone photopigment anomolous in having a shifted peak sensitivity

Answer 13

Trichromats

Question 14

Retinal photoreceptors serve to convert ___energy to ____energy buy virtue of their special cellular structure consisting of an inner cell body and an outer segment of photopigment

Answer 14

Photonics
Chemical

Question 15

In light, ___ is stimulated , starting a cascade involving transduction and phosphodiesterase (PDE)

Answer 15

Rhodopsin

Question 16

____ are low resolution while ___ are high resolution

Answer 16

Rods
Cones

Question 17

_____ cells connect photoreceptors laterally and dampen cells surrounding the centre of maximal receptive stimulation

Answer 17

Horizontal

Question 18

___ cells are receptive fields for ganglion cells

Answer 18

Cone

Question 19

_____ cells seRve one based receptive fields

Answer 19

Ganglion

Question 20

Cone photoreceptors often synapse with 2 different types of ganglion cells : ___ and ____ ganglion cells

Answer 20

On and off centre

Question 21

________- peripheral cones connect to more horizontal cells which inhibit those neighbouring cells getting weaker stimuli , optimizing acuity

Answer 21

Lateral inhibition

Question 22

Visual pathway from eye to brain :
___ nerve, ___, ___ tract , ____, _______

Answer 22

Optic nerve
Optic chiasm
Optic tract
Thalamus
Occipital lobe

Question 23

What Visual acuity is considered legally blind?

Answer 23

20/200