Visual Fields and Lesions

Question 1

what is viewed by the eyes is called

Answer 1

visual field

Question 2

closest to the nose

Answer 2

nasal hemiretina

Question 3

closest to the temples

Answer 3

temporal hemiretina

Question 4

vertical line division of retina

Answer 4

temporal and nasal

Question 5

horizontal division of retina

Answer 5

superior and inferior hemiretinas

Question 6

how many superior and inferior hemiretinas are there?

Answer 6

4
makes up the superior nasal & superior temporal and inferior nasal and interior temporal

Question 7

where do images from the temporal visual field project to

Answer 7

nasal hemiretina

Question 8

where do images from the nasal vf go to

Answer 8

temporal hemiretina

Question 9

where do images from the superior hemiretinas project to?

Answer 9

inferior hemiretina

Question 10

where do images from the inferior vf project to?

Answer 10

superior hemiretina

Question 11

explain what happens when we are looking to the right in terms of hemiretinas

Answer 11

(lands to L side of the brain)
lands on nasal hemi ipsilaterally
lands on temporal hemi contralaterally

Question 12

ceileing

Answer 12

lands on inferior hemi

Question 13

floor

Answer 13

lands on superior hemi

Question 14

what happens with tunnel vision

Answer 14

loss of both peripheral visual fields
loss of crossing fibers which come from both hemiretinas of the temporal
lesion at the chiasm
bitemporal heteronymous

Question 15

what could cause tunnel vision

Answer 15

tumor at the pituitary gland puts pressure here causing these symptoms

Question 16

one eye is losing the half of its nasal visual field and the other sees all of it
able to function mostly normally because you have some good vision so it overrides the bad vision

Answer 16

ispilateral nasal hemianopsia

Question 17

taking out a quadrant (¼) of the eyes visual field

Answer 17

contralateral homonymous hemianopsia

Question 18

complete interruption of what nerve cause permanent blindness of that eye (one eye) and if CN III is in tact the blind eye can still respond to light reflex (think acoustic reflex in dead ear)

Answer 18

cn II

Question 19

can i shine light and blind eyeball and them constrict?

Answer 19

no because the vision has to trigger it so will not receive a direct constrict in the blind eye

Question 20

do two reflexes (auditory and light) involve the cortex?

Answer 20

no, bs & thalamus mediated (subcortical)

Question 21

blindness in R eye and shine light into the L eye, the L pupil constricts, should the R eye also constrict?

Answer 21

yes as long as CN III is in tact

Question 22

Blindness in the nasal half of the retina or the temporal half of the visual field of each eye
Midline lesion of the optic chiasm

Answer 22

tunnel vision
Bitemporal heteronymous hemianopsia

Question 23

ballooning of thinning wall of the artery

Answer 23

aneurysm

Question 24

Nasal visual field is lost on one side
Interruption of non-decussating fibers
Possibly due to an aneurysm of the internal carotid

Answer 24

ipsilateral nasal hemianopsia

Question 25

usually secondary to stroke, head trauma, or tumors.
Could be either side

Answer 25

contralateral homonymous hemianopsia

Question 26

Light reflexes may be intact but the visual information never reaches the primary visual cortex
Stroke, trauma or loss of oxygen and blood supply to the geniculostriate fibers or striate cortex

Answer 26

cortical blindness

Question 27

what is macular sparing?

Answer 27

Even if the calcarine artery is occluded, there may still be some blood supply to the foveal or macular region by the middle cerebral artery
macular redundancy/circle of willis

Question 28

Interruption of the pathways from the ipsilateral upper temporal quadrant of the retina and the contralateral upper nasal quadrant pf the retina
Lesion in the cuneus (primary visual cortex above the calcarine sulcus)
So two lower visual field quadrants are blind

Answer 28

contralateral lower quadrantic anopsia