visual system

Question 1

the eye

Answer 1

a globe that is filled with fluids
-composed of various layers

Question 2

3 layers of the eye

Answer 2

outer, middle, and inner layer

Question 3

outer layer

Answer 3

contains the sclera and cornea

Question 4

middle layer

Answer 4

choroid with blood vessels and nerves

Question 5

inner layer

Answer 5

retina
-light sensing part of the eye

Question 6

2 fluids of the eye

Answer 6

aqueous and vitreous humor

Question 7

aqueous humor

Answer 7

thin watery fluid
-anterior to lens but between lens and cornea
-contains nutrients for cornea and lens

Question 8

viterous humor

Answer 8

thick jelly like semifluid
-posterior to the lends but between the lens and retina
-maintains shape of eye

Question 9

cornea

Answer 9

clear part that we see through
-front of eye
-outermost front

Question 10

anterior chamber

Answer 10

directly under the cornea
-contains aqueous humor

Question 11

lens

Answer 11

behind the cornea that changes shape
-helps focus
-gives us the pupil

Question 12

iris

Answer 12

holding lens in place
-gives us the color

Question 13

ciliary body

Answer 13

helps tighten or loosen fibers
-lateral to zonula fibers

Question 14

posterior chamber

Answer 14

small space before/on the side of the lens
-contains aqueous humor

Question 15

sclera

Answer 15

white of the eye
-outermost layer around the eye

Question 16

zonula fibers

Answer 16

around lens on the sides to help hold in place

Question 17

choroid

Answer 17

vascular layer that provides blood supply and nutrients
-vascularized
-between sclera and retina

Question 18

retina

Answer 18

visual sensing layer that contains rods and cones
-below the choroid layer

Question 19

optic disk

Answer 19

back of the eyeball where retinal arteries and veins come into
-can create a blindspot
-medial side at the back side of the eye

Question 20

fovea

Answer 20

area of higher visual ability
-focus
-lateral of the optic disk

Question 21

rectus tendon

Answer 21

how the eye muscles attach
-on both sides, will have a medial and lateral one

Question 22

subarachnoid space

Answer 22

following from meninges
-the “window to the CNS”
-at the back side coming off the eye

Question 23

retinal arteries and veins

Answer 23

runs in alongside the CN 2 and into the retina

Question 24

optic nerve (CN 2)

Answer 24

at back of the eye and comes inward to the retina
-enters at the optic disk

Question 25

canal of schlemm

Answer 25

allows for fluids to go into the eye

Question 26

conjunctiva

Answer 26

tissue that helps hold the eyeball in place of lateral edges

Question 27

ora serrata

Answer 27

jagged edge where the retina is ending and we will have the ciliary muscle above it

Question 28

macula

Answer 28

the area surrounding the fovea
-rich in cones but not rods

Question 29

what are the two photoreceptors of the retina

Answer 29

rods and cones

Question 30

rods are good for what vision

Answer 30

black, white and gray vision
-night vision

Question 31

cones are good for what vision

Answer 31

color vision
-high visual acuity

Question 32

how does stimulation of rods and cones work

Answer 32

the stimulus strokes the rods and cones, graded receptor potentials will occur, excitation is passed to cells of the retina and when the retinal ganglion cells receive the excitation AP are generated

Question 33

bigger light results in ______________

Answer 33

bigger excitation

Question 34

retinogeniculostriate pathway

Answer 34

retina to V1
-ganglion cells of CN 2 to optic chiasm, fibers leave lateral geniculate nucleus to the internal capsule and become optic radiations, projects to visual cortex above or below the calcarine sulcus

Question 35

retinohypothalamic pathway order

Answer 35

retinal ganglion cells axons of CN II pass to the optic chiasm where some decussate and enter either the left or right optic tract. Most fibers in the optic tracts terminate in the lateral geniculate nucleus of the thalamus. From the thalamus, project to internal capsule to optic radiation (V1) to above or below calcarine sulcus (lingual/cuneus gyrus)

Question 36

light reflexes

Answer 36

bright light directed into one eye causes pupils of both eyes to constrict

Question 37

accommodation reflex

Answer 37

accommodation- eyes changing shape as we age, why we need reading glasses when we’re older

Question 38

convergence reflex

Answer 38

convergence- eyes coming together via the medial rectus to focus on a close object (cross-eyed)