Sensory system - Visual system
22 important questions on Sensory system - Visual system
Why does the light has to cross many layers before reaching the photo receptors?
There is no yellow cone, how can this colour still be distinguished?
There are two types of axons that leave the eye, which two?
- Higher grades + faster learning
- Never study anything twice
- 100% sure, 100% understanding
What is the target of the retinal projections?
2. Superior colliculus and pretectum = 10%
3. Suprachiastmatic nucleus (some)
What is the function of the suprachiasmatic nucleus?
What is the function of the pretectum?
What is special about the lateral geniculate body (thalamus)?
Layered structure (6) --> each receives input from a specific type of ganglion (3 types)
Where is the lateral geniculate nucleus connected to?
--> way more neurons from LGN to V1 than from eye to LGN, because the amount of information increases
How many routes to V1 from LGN exist?
--> damaged separately --> quadrant anopsia
What is quadrant anopsia?
Meyer's loop (via temporal lobe) = missing left/right upper quarter (lower part of retina)
Barum's loop (via parietal lobe) = missing left/right lower quarter
(upper part retina)
Does the information from the LGN to the cortex still arrives separately for each eye?
What is the effect of ventral stream lesion on the right side?
(V1 -> temporal lobe)
But Galvanic skin response remains present, the limbic system still recognizes the face (but consciousness is not present)
Can also be the other way around -> Capgras delusion
--> Unilateral right-sided lesion
What happens when there is damage to the left side ventral stream?
V1 -> parietal lobe
--> unilateral left sided lesion
What happens when there is damage to the dorsal stream?
What are saccadic eye movements?
Only central (macular) vision is sharp and in color, but it has an angle of vision of only a few degrees of arc.
Peripheral vision is unsharp and in black and white, but wide angled.
What is the effect on the visual field of an infartion of the basilar artery?
What is the structure of the rods and cones
outer segments are renewed continuously
Which receptor is present in the rods and which in the cones?
Cones = iodopsin
G-protein coupled receptors
What happens when iodopsin absorbs light?
Why is there a constant 'depolarization' in the eyes?
What happens in the light and dark with the sensitivity of vision?
Light: break down into retinal and opsin happens due to light which reduces sensitivity
Dark: build up of opsin which increases sensitivity
Tell something about the synthesize speed of cones/rods
Rods = resynthesize slow but sensitivity is high
The question on the page originate from the summary of the following study material:
- A unique study and practice tool
- Never study anything twice again
- Get the grades you hope for
- 100% sure, 100% understanding