Motor Control 2 Flashcards
I Molecular Layer
Mostly axons
II External Granular
Small neurons (granular cells) and large pyramidal cell neurons
III External Pyramidal
- small to medium pyramidal cells
- dendrites to layer I
- axons to deeper layers
IV Internal Granular
- Smooth and spiny Stellate cells
- target for ascending sensory information to thalamus
V Internal Pyramidal
- medium to large pyramidal cells
- dendrites extend upward 1 to 2 layers
- major source of cortical efferent fibers
VI Multiform Layer
- assortment of neurons, some pyramidal and fusiform cell bodies
- axons project to thalamus
Where do Betz Cells project?
Most common in motor cortex projecting to anterior horn of lumbosacral spinal cord
What type of pyramidal cells lie in layers 2, 3, 5, and 6?
2 and 3: association fibers
5: give rise to fibers going to subcortical structures
6: give rise to fibers going to thalamus
Where do most thalamocortical axons terminate?
Layer IV
But also some on III and VI
Lateral internal medullary lamina of thalamus
Dorsal and lateral tier containing 4 major nuclei
VA, VL, VPL, VPM
What does stimulation of SMA envoke?
Movements involving sequences or groups of muscles serving to orient body or limbs in space
Likely involved in organizing or planning sequences of muscle activation
Which cortex likely organizes postural adjustments to move?
Pre-motor cortex
Area 5 of posterior parietal cortex
Extensive projections from somatosensory cortex and input from vestibular system
Active reaching for a specific target of interest
Area 7 of posterior parietal cortex
Processes visual information related to location of objects in space
Very active when eye fixates on a target and hand reaches for it
