Week 6: Peripheral Visual System

Question 1

Outer fibrous layer of the eye that becomes the transparent cornea at the front

Answer 1

SCLERA

Question 2

Eye structure that includes the retina and photoreceptor cells

Answer 2

INNER LAYER (NEURAL RETINA)

Question 3

Accessory eye structures that help focus and transmit light

Answer 3

CORNEA, AQUEOUS HUMOR, IRIS, LENS, VITREOUS HUMOR

Question 4

Location of photoreceptors in the eye

Answer 4

RETINA

Question 5

Transparent part of the eye where refraction begins

Answer 5

CORNEA

Question 6

Elastic structure that adjusts curvature to focus on near and far objects

Answer 6

LENS

Question 7

Muscles that control lens shape for accommodation

Answer 7

CILIARY MUSCLES

Question 8

Muscles that adjust pupil diameter in response to light

Answer 8

PUPILLARY MUSCLES

Question 9

Adjustments involving convergence, accommodation, and constriction for near vision

Answer 9

NEAR RESPONSE

Question 10

Photoreceptor-free pit in retina with highest visual acuity

Answer 10

FOVEA

Question 11

Photoreceptors specialized for low-light (scotopic) vision

Answer 11

RODS

Question 12

Photoreceptors specialized for daylight (photopic) and color vision

Answer 12

CONES

Question 13

Chromatic photoreceptor subtypes for color sensitivity

Answer 13

L-CONE, M-CONE, S-CONE

Question 14

Structure in photoreceptors where light-absorbing pigments are located

Answer 14

OUTER SEGMENT (DISK STACKS)

Question 15

Pigment found in rods formed by 11-cis-retinal and opsin

Answer 15

RHODOPSIN

Question 16

Process of light reducing cGMP levels and closing Na+/Ca2+ channels

Answer 16

HYPERPOLARIZATION (RECEPTOR POTENTIAL)

Question 17

Standing ionic current in photoreceptors in darkness

Answer 17

DARK CURRENT

Question 18

Molecule activated by light that initiates phototransduction cascade

Answer 18

RHODOPSIN (Rh*)

Question 19

Secondary messenger whose decrease closes ion channels in photoreceptors

Answer 19

CYCLIC GMP

Question 20

Enzyme activated during phototransduction that degrades cGMP

Answer 20

PHOSPHODIESTERASE (PDE)

Question 21

Photoreceptor adaptation mechanism that adjusts cGMP production via calcium feedback

Answer 21

LIGHT ADAPTATION

Question 22

Slow recovery of rod function after exposure to bright light

Answer 22

DARK ADAPTATION

Question 23

Pathway where photoreceptors synapse directly on bipolar cells

Answer 23

DIRECT PATHWAY

Question 24

Retinal interneurons that provide lateral input to bipolar and ganglion cells

Answer 24

HORIZONTAL AND AMACRINE CELLS

Question 25

Retinal ganglion cells receive input from photoreceptors via these cells

Answer 25

BIPOLAR CELLS

Question 26

Center-surround receptive field structure of RGCs enabling contrast detection

Answer 26

ANTAGONISTIC CENTRE-SURROUND

Question 27

RGCs excited by light in the center and inhibited by light in the surround

Answer 27

ON-CENTRE CELLS

Question 28

RGCs inhibited by light in the center and excited by light in the surround

Answer 28

OFF-CENTRE CELLS

Question 29

Glutamate receptor type that hyperpolarizes ON bipolar cells in darkness

Answer 29

METABOTROPIC GLUTAMATE RECEPTORS

Question 30

Glutamate receptor type that depolarizes OFF bipolar cells in darkness

Answer 30

IONOTROPIC GLUTAMATE RECEPTORS

Question 31

ON-centre cells respond most to red center, green surround; OFF-centre is the opposite

Answer 31

COLOR OPPONENCY: RED-GREEN

Question 32

ON-centre cells respond most to blue center, yellow surround; OFF-centre is the opposite

Answer 32

COLOR OPPONENCY: BLUE-YELLOW

Question 33

Property of foveal RGCs allowing high resolution and low convergence

Answer 33

SMALL RECEPTIVE FIELD

Question 34

Peripheral rod pathways allowing detection of dim light but with low acuity

Answer 34

LARGE RECEPTIVE FIELD AND HIGH CONVERGENCE

Question 35

Primary neurotransmitter released by photoreceptors

Answer 35

GLUTAMATE

Question 36

Voltage-gated channels in photoreceptors that trigger neurotransmitter release

Answer 36

CALCIUM CHANNELS

Question 37

Functional organization of retina that enables detection of contrast and motion

Answer 37

CENTRE-SURROUND ORGANISATION