vision

Question 1

what does the vision system include

Answer 1

eye
optic nerve
optic chiasm
optic tracts
visual cortex

Question 2

how does light travel

Answer 2

straight lines

Question 3

how does light first enter the eye

Answer 3

through the cornea and pupil

Question 4

what part of the eye controls how much light enters by changing shape

Answer 4

iris

Question 5

which part of the eye does light refract in

Answer 5

the lens and then it bends to converge onto the retina

Question 6

what happens to the lens when focusing on a near object

Answer 6

lens thickens to increase refraction

Question 7

what happens to the lens when focusing on a far away object

Answer 7

lens flattens

Question 8

which part of the retina does the light hit

Answer 8

photoreceptors

Question 9

what is the function of the photoreceptors

Answer 9

to fire and sends electrical signals to the brain

Question 10

which nerve carries the signals from the photoreceptors

Answer 10

optic nerve

Question 11

where does the information from the eyes have to travel to before it can be turned into conscious vision

Answer 11

back of the brain

Question 12

where do the two optic nerves first converge at

Answer 12

optic chiasm - a crossover junction

Question 13

after receiving information from each retina where does it then go to

Answer 13

left retina to left optic tract
right retina to right optic tract

Question 14

where does each optic tract end

Answer 14

lateral geniculate nucleus

Question 15

what is the lateral geniculate nucleus part of

Answer 15

thalamus

Question 16

where does the signals from the end of the optic tract continue to

Answer 16

visual cortex via bands of nerve fibres called optic radiation

Question 17

when light enters the eye, what reaction does it trigger

Answer 17

photochemical reactions in rods and cones at the back of the retina

Question 18

what does the chemical reaction activate

Answer 18

bipolar cells which sends information to the visual cortex via the thalamus

Question 19

what are the first order neurons in the vision system

Answer 19

bipolar cells of the retina that receives visual info from the rods and cones

Question 20

what are the second order neurons in the vision system

Answer 20

ganglion cell of the retina
its axons lie in the optic nerve and continue through the optic chiasm and proximal part of the optic tract of the opposite side

Question 21

what are the third order neurons in the vision system

Answer 21

lateral geniculate nucleus in the thalamas