Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

SF2 Exam III > Visual Systems Norden > Flashcards

Visual Systems Norden Flashcards

1
Q

Purpose of saccades

A

saccades constantly refresh image to look for changes in environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

optic nerve is composed of what?

A

retinal ganglion cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

optic nerve is surrounded by what? What layer is continuous with sclera of eye?

A

dura***, arachnoid, pia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What goes through optic chiasm? What crosses at the optic chiasm?

A

axons of all RGCs from each eye go through optic chiasm.

Axons from RGCs of the nasal half of both eyes cross to go contralaterally, temporal axons travel ipsilaterally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does the optic tract course?

A

optic tract travels posteriorly and courses around the crus cerebri. optic tract ‘hugs’ the interpeduncular fossa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

4 main targets of RGCs and function of each?

A

LGN of Thalamus (form color and movement)
Superior Colliculus (generate eye movements, visual reflexes)
Pretectum of midbrain (pupillary light reflex)
Hypothalamus (circadian rhythm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

location of LGN in thalamus

A

posterior and lateral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what layers of the LGN receive input from contralateral eye?

A

Layers 1, 4, and 6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what layers of the LGN receive input from ipsilateral eye?

A

layers 2, 3, and 5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

LGN processes info from what parts of visual field?

A

processes info from contralateral visual hemifield

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how is the binocular portion of vision processed in LGN

A

given point in the binocular visual field is represented by a column of neurons extending through all 6 layers of the LGN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the blood supply to the LGN?

A

primarily by the anterior choroidal artery (from internal carotid) and branches of the posterior cerebral artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

parvocellular layers of LGN represent which layers and process what information?

A

Layers 3-6 process color and form vision (central retina)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

magnocellular layers of LGN represent which layers and process what information?

A

Layers 1-2 process information from retinal ganglion cells signaling “movement” (peripheral retina)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

LGN neurons project to Area 17 through what tract? (2 names)

A

geniculo-calcarine tract / optic radiations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

optic reactions are part of what subdivision of the internal capsule?

A

retrolenticular division of the posterior limb of the internal capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Axons coming out of the medial part of the LGN pathway

A

courses dorsally over the lateral ventricle (through parietal lobe) and then in the internal capsule to enter the cuneus gyrus of the calcarine cortex (17)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Axons coming out of the lateral portion of the LGN pathway (Meyer’s Loop)

A

course rostrally around the temporal horn of the lateral ventricle (through the temporal lobe), then enter the internal capsule to enter the the lingual gyrus of the calcarine cortex ( 17)

19
Q

Blood supply to the optic radiations?

A

middle and posterior cerebral arteries

20
Q

Blood supply to the posterior limb (retrolenticular division) of the internal capsule?

A

middle cerebral artery

21
Q

extrastriate visual area definition

A

other higher-order visual cortical areas in occipital, temporal, and parietal lobes which area 17 projects to

22
Q

extrastriate areas for ‘where’ and ‘what’ consist of which lobes?

A

where - occipital and parietal lobes

what - occipital and temporal lobes

23
Q

RGC to superior colliculus serve what specific function?

A

play a role in “orienting” to moving stimuli and in directing gaze

24
Q

cells in the superior colliculus are very sensitive to what?

A

movement

25
Q

pulvinar is located where?

A

nucleus located in dorsal thalamus

26
Q

pathway of superior colliculus projection to cortex?

A

RGCs -> Superior Colliculus -> Pulvinar -> Extrastriate Visual Cortex

27
Q

what type of RGCs project to the hypothalamus and to what nucleus?

A

primitive light sensitive RGCs that respond to ambient light; suprachiasmatic nucleus of hypothalamus

28
Q

function of RGC projections to hypothalamus?

A

linking circadian rhythms/hormonal cycles with ambient illumination; also involved in projections to the reticular formation for regulation of sleep/wake cycles

29
Q

progressive encephalization definition

A

processing of visual information in higher order areas of brain

30
Q

individuals with lesions only in area 17 present with…?

A

“blindsight” - functionally/cortically blind

individuals can still see light, even though they are not consciously aware of it

31
Q

individuals with lesions only in occipital lobe present with…?

A

cortical blindness but deny blindness

32
Q

visual agnosia is what and occur how?

A

individual is not blind, but fails to recognize the identity, significance or some other aspect of an object which is seen
occurs from lesions of higher order visual areas with an intact Area 17

33
Q

object agnosia occurs from?

A

lesion of area 18, inability to recognize an object on the basis of sight alone

34
Q

prosopagnosia presentation and cause

A

inability to match a “face” with an “identity”

bilateral lesion of higher order temporal lobe visual area

35
Q

only place in the body where blood vessels and CNS tissue can be observed directly

A

fundus

36
Q

optic disc location in fundoscopy

A

nasal (medial) to macula (central retina)

37
Q

papilledema presentation in fundoscopy and cause

A

caused by increased ICP

disc is elevated or swollen, darker than normal, or the disc edges are blurred

38
Q

Why does the disc appear swollen when there is increased intracranial pressure?

A

pressure is transmitted in the subarachnoid space surrounding the nerve; increased intracranial pressure impedes the return of venous blood from the eye and causes the nerve head to be congested and to appear dark pink

39
Q

main causes of optic disc swelling not caused by papilledema?

A

hypertension (bilateral) and optic neuritis

40
Q

optic neuritis presentation and it is a presenting sign for what condition?

A

multiple sclerosis
can affect the pupillary light reflex
upon stimulation of the affected eye, the direct reflex will be “sluggish” relative to the direct response of the unaffected eye
relative afferent pupillary defect RAPD (Marcus Gunn pupil)

41
Q

Shaken Baby Syndrome can lead to death by what?

A

subdural hematoma

subsequent brain herniation or brainstem avulsion - separation of the brain at the junction of the pons and medulla

42
Q

signs and symptoms for shaken baby syndrome

A
  1. Ecchymosis (bruising) on the sternum
  2. Presence of retinal hemorrhage (>3 wks age), papilledema, retinal detachment
  3. A decreased responsiveness
43
Q

long term consequences of SBS

A
  1. Diffuse axonal injury
  2. Blindness
  3. Epilepsy, intellectual impairment, etc

SF2 Exam III (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions