FE: Lecture 8: Visual

Question 1

What makes up anterior and posterior part of eye?

Answer 1

cornea which contains aqueous humor

iris muscle and pupil

lens and ciliary muscle

Question 2

What is in the vitreous chamber?

Answer 2

vitreous humor

retina(optic disk and nerve)

fovea and maccula

Question 3

What are the layers of the retina?

Answer 3

1. nucleus and plexiform layers
2. receptor layer- rods, cones and pigmented epithelial
3. bipolar cell layers- use local potentials to go to ganglion cells
4. ganglion cell layers- projects to thalamus and superior colliculus

Question 4

What do the rods do best in regards to vision?

Answer 4

they are more sensitive to light but have low amplitude threshold

do not distinguish light but have better sense of acuity

Question 5

What do cones do best in regards to vision?

Answer 5

higher amplitude required, detects color/frequency and wave length of light

color blindness is lack of cones

Question 6

What does RBG and LMS mean?

Answer 6

red (low frequency) green blue (high frequency)

long medium short

Question 7

What is the definition of acuity?

Answer 7

ability to resolve small details, depends on number of receptors

Question 8

What comprises the central retina?

Answer 8

the macula and fovea- central 10 degrees a huge number of cones and rods

Question 9

What comprises peripheral retina?

Answer 9

few rods and cones

Question 10

Where is color vision best in?

Answer 10

central retina

Question 11

Where is acuity in normal light best in?

Answer 11

central

Question 12

Where is acuity from low light best in?

Answer 12

just outside central

Question 13

What does the brain need to do for best acuity?

Answer 13

it must aim the fovea at whatever it needs to see for high acuity

Question 14

Where is the head of the optic nerve?

Answer 14

nasal retina

Question 15

Where is your blind spot?

Answer 15

temporal visual field

Question 16

What is the pathway of conscious vision?

Answer 16

Retina to lateral geniculate nucleus via optic nerve and tract

then LGN to primary visual cortex V1

Question 17

What is pathway of unconscious vision?

Answer 17

Retina to tectum via optic nerve and tract

superior colliculus- optokinetic reflex

pretectal area- pupil constriction

Question 18

Do ganglia neurons in nasal retina cross?

Answer 18

Yes at midline to LGN

Question 19

Do ganglia in temporal retina cross?

Answer 19

No

Question 20

Where does the right visual field of the left eye transmit to?

Answer 20

left visual cortex

Question 21

Where does the right visual field of the right eye transmit to?

Answer 21

left visual cortex

Question 22

Where do inferior and superior visual fields transmit to?

Answer 22

inferior VF to superior V1 cortex

superior VF to inferior V1 cortex

the macula goes to posterior cortex

Question 23

If there is a monocular scotoma in the right eye nasal field where would damage be for you not to see?

Answer 23

temporal retina

Question 24

If you had damage to right eye nasal and temporal field what would be damage ?

Answer 24

right optic nerve

Question 25

If the temporal fields of both eyes are damaged what is leading to loss of vision?

Answer 25

optic chaism

Question 26

If there is loss of vision in both left visual fields of both eyes why can’t you see?

Answer 26

damage to right optic tract, LGN or optic radiations

Question 27

If you can’t see in both left visual fields except for macula what is the reason?

Answer 27

right visual cortex, partial lesion

Question 28

What is pathway of pupillary reflex?

Answer 28

1. light into eye then optic nerve to pretectal nucleus
2. pretectal nucleus to EWN
3. Oculomotor nerve to ciliary ganglia (parasympathetic)
4. both pupils constrict bc it goes to both EWN via posterior commissure

Question 29

Do you need the visual cortex for this reflex?

Answer 29

No