Vision Flashcards
(34 cards)
Where does the blind spot for each eye occur in the visual field?
Slightly lateral.
How much overlap is there between the right and left visual fields?
60%.
What exists after the optic track before the optic radiations?
Lateral geniculate nucleus.
The upper optic radiations correspond to the ___ visual field, and the lower optic radiations correspond to the ___ visual field.
Inferior/lower, superior/upper.
Where is Myer’s loop located?
Lower optic radiations.
What area # is the primary visual cortex (occipital cortex)?
17.
What does the “where pathway” cover and how does it run?
Analysis of motion and spatial relations. Runs superiorly.
What does the “what pathway” cover and where does it run.
Analysis of form and color. Inferolaterally.
Where does information travel after the visual cortex (area 17)?
To the superior colliculus for sensory input integration (saccades in reticular formation and SC for head orientation).
Where does vision input go after area 17?
18 and 19, then to the dorsal and ventral stream.
The dorsal stream is the ___ pathway, and the ventral stream is the ___.
Where (posterior parietal), what (inferotemporal cortex).
T/F: the ventral stream opperates in dim light.
False, the dorsal “where” stream.
The ___ stream is action vision and contains information about object characteristics that guides actions.
Dorsal “where” stream.
What pathology is linked with disruption/lesion to the visual streams. Give one for each.
VENTRAL
-visual agnosia
DORSAL
- optical ataxia
- cannot conform or reach in right direction
Where is optical flow processed and why is it important?
Posterior parietal lobe. Important for visual proprioception; object viewing at distance.
Which are more central, rods or cones?
Cones.
What type of neuron is the retina?
Bipolar ganglion.
What is the role of the lateral geniculate nucleus?
Relay nucleus of thalamus.
What part of the internal capsule do fibers arise from the lateral geniculate nucleus?
retro and subleticular portion.
What does a superior colliculus lesion cause?
Inability to oreint to contralateral visual stiumuli
What do the retinohypothalamic fibers influence?
Circadian rhythm
- eating
- drinking
- hormones
- temp
While the ventral stream is used more for conscious awareness, what happens after input goes through the dorsal stream?
To be used in motor control.
Name the 4 parts of the diencephalon.
- Epithalamus
- Subthalamus
- Hypothalamus
- Thalamus (dorsal, 80% diencephalon)
T/F: almost all sensory pathways relay in thalamus.
True.
