NEUR532 - Visual System Flashcards
Strcture of the eye
Describe the visual pathway in humans
Describe the layered structure of the primate lateral geniculate nucleus (Body)
Describe the pattern of ganglion cell inputs from the two ees to different layers of the lateral geniculate nucleus
Describe the position and cytoarchituecture of the priate striate cortex
Describe the input-output organization of different layers of the striate cortex (Brodmans area 17 or V1 primary visual cortex)
Describe the segregation of inputs of inputs from different layers of the LGN t layer IVC of the striate cortex
Describe the proection of layer IVC neurons to other layers of the striate cortex
Describe how the projections from one eye to the LGN and striate cortex may be demonstrated anatomically
Explain what is meant by “ocular doinance column” and “blobs” in the striate cortex
What are 2 other names for the striate cortex
- Primary visual cortex (V1)
- Brodmanns area 17
What is the point-to-point projection from retina
- To the dorsal nucleus of the LG body of the thalamus
- V1
- Occipital
- Temporal
- Parietal
The retinofugal projection
Where does sensory information decuss in the spinal cord? KNOW
Where do fibres of the optic tract terminate?
In the dorsal nucleus
How many layers does the LG body have?
6 distinct layers
2 x - Magnocellular LGN neurons: L peripheral fields - transient response
4 x layers - Parvocellular LGN cells: small centre-surround fields - sustained response
Whats another term for LGN?
Lateral geniculate body
Where do cossed fibres end in layers?
- 1, 4, 6
Uncrossed fibres end in what layers?
2, 3, 5
What are koniocellular layers?
- VERY TINY
- ## Visual colour acuity
where is the calcaraine fissure?
- Associated with primary visual cortex (v1) striate cortex
Learn the optic radiations and meyers loop
How are visual projections organised?
Topographically
What is the largest layer of the striate cortex?
IV
Learn the layers of the striate cortex
Where to magnocellular LGN neurons project primarily to?
IVC alpha
Where to parvocellular LGN neurons project mainly to?
IVC beta
Where do Koniocellular LGN axons make synapses primarily?
Layers I - III
- Colour information
DRAW THESE OUT AND LEARN
What primary visual cortex layer has ocular dominance columns?
Layer IV
Revealed by radioactive amino acid tracers
What did he cytochrome oxidase technique reveal?
Blobs: cylindrical pillars in striate cortex
Layer IV
What do blob regions do?
UNDERSTAND THE PARALLEL PATHWAYS of blob regions
Where is the LGN located?
What is the dorsal stream associated with?
- Visual motion
- Visual control of action
- Parietal lobe
What is the ventral stream associated with?
- Perception of the visual world
- Object recognition
- Temporal lobe
What does the pretectal area do?
- Control pupil size
- Small group of nuclei
- PARTICIPATES IN PUPILLARY LIGHT REFLEX
What is the superior colliculus associated with?
- Eye oritentation to new stimuli
- Moves fovea to objects of interest
DRAW OUT NEURAL PATHWAY INVOLVED IN THE PUPILLARY LIGHT REFLEX
What does the superior colliculus contribute to?
- Voluntary and involuntary eye movement
- Head movement for fixation and gaze
What is the suprachiasmatic nucleus associated with?
- Circadian rhythm synchronization
- Ambient light
What does the accessory optic tract innervate?
Cerebellum
What nuclei does the accessory optic tract innervate the cerebellum?
- The tegmentum nuclei
- Inferior olivary nuclei
