147 & 148 Visual system I and II

Question 1

where does the optic nerve terminate

Answer 1

lateral geniculate nuclei of the thalamus

Question 2

what does the fibrous layer consist of

Answer 2

sclera and cornea

Question 3

what is the purpose of the middle (vascular) layer

Answer 3

focusing and regualting the intensity of light

Question 4

what does the cilliary body produce

Answer 4

aqueous humor

Question 5

contraction of the cilliary muscles result in

Answer 5

decreased tension on suspensory ligament, allows lens to increase in thickness, focusing light rays on near object

Question 6

constrictor muscle is under the influence of

Answer 6

parasympathetics

Question 7

dilarot muscle is under the influence of

Answer 7

sympathetic control

Question 8

what does light pass through

Answer 8

cornea, aqueous humor, lens vitreous body

Question 9

what is the main refractive structure of the eye

Answer 9

cornea

Question 10

when aqueous humor is drained it goes through

Answer 10

trabecular meshwork and into the sinus venosus sclerae

Question 11

what happens when aquous humor fails to drain

Answer 11

increases intraocular pressure, leads to glaucoma

Question 12

what does the term presbyopia mean

Answer 12

failure of the lens to accomadate, happens with age

Question 13

what is opacification of the lens called

Answer 13

cataract

Question 14

what is the condition when debris from photoreceptor cells accumulate between the photoreceptor cell layer and the pigment epithelial layer

Answer 14

retinitis pigmentosa

Question 15

rods are sensitive to

Answer 15

light

Question 16

cons are responsible for

Answer 16

color

Question 17

what is more pedominate in the peripheral zone

Answer 17

rods

Question 18

the fovea only consist of

Answer 18

cones

Question 19

what is the first order neuron of rods and cones? second order neuron

Answer 19

bipolar cell, ganglion cell

Question 20

which cells modulate transmission between photoreceptor and bipolar cells

Answer 20

horizontal

Question 21

what cells modulate transmission between bipolar and ganglion cells

Answer 21

amacrine

Question 22

what is the area for acute vision

Answer 22

fovea

Question 23

what happens to rhodopsin when absorbing light and where is it found

Answer 23

in rods, rhodopsin is broken down into retinal and opsin, dependent on vitamin A

Question 24

where is iodopsin

Answer 24

cones

Question 25

what matte surroudns the optic nerve

Answer 25

dura arachnoid and pia

Question 26

what is papilleddema

Answer 26

when the optic nerve becomes compressed

Question 27

where is the primary visual cortex

Answer 27

medial surface of the occipital lobe

Question 28

which visual field forms meyers loop and passes inferiorly

Answer 28

superior visual field

Question 29

visual defects are ______ when confined to the same part of the visual field in each eye

Answer 29

homonymous

Question 30

lesions in front of the optic chiasm are

Answer 30

heteronymous

Question 31

lesions distal to optic chiams are

Answer 31

homonymous

Question 32

total destruction of the optic tract, lateral geniculate nucleus, or visual cortex results in

Answer 32

loss of entire opposite field of vision

Question 33

what three reflexes dictate size of pupil and curvature of the lens

Answer 33

light or pupillary constriction reflex
pupillary dialation reflex
accommodation reflex

Question 34

int he light reflex, impulses enter the

Answer 34

brachium of the superior colliculus

Question 35

consensual light reflex involves

Answer 35

contralateral edinger-westphal nucleus

Question 36

what is the near triad

Answer 36

convergence of the eyes, pupillary constriction, thickening of lens

Question 37

what nuclei is responsible for convergence of the eye

Answer 37

somatic nuclei

Question 38

horner syndrome is the loss of ______ to one side of the face

Answer 38

sympathetics