Brain Control of Movement Flashcards
What do lateral pathways control?
Voluntary movements of distal movements
What do ventromedial pathways control?
Posture
Locomotion
What is the main tract involved in the lateral pathways?
Corticospinal tract
What areas of the brain does the CST originate from?
Areas 4 and 6 of frontal motor cortex (rest is somatosensory)
Where does the CST decussate?
Medulla/spinal cord junction
Where do CST axons synapse?
Ventral horn motor neurones and interneurones
Where does the rubrospinal tract start?
Red nucleus of midbrain
What is the result of lesions involving the CST and RST?
Loss of fine movements of arms and hands
What is the result of lesions involving the CST?
Loss of fine movements, functions reappear after a few months
What is the function of the vestibulospinal tract?
Stabilizes head and neck
What is the function of the tectospinal tract?
Ensures eyes remain stable as body moves
What are the 2 ventromedial pathways that control posture and locomotion?
Vestibulospinal tract
Tectospinal tract
What are the ventromedial pathways that control trunk and antigravity muscles?
Pontine and medullary reticulospinal tracts
Where do the pontine and medullary reticulospinal tracts originate?
Brainstem
What is the function of the PRT and MRT?
Maintain balance and body position
Where is the primary motor cortex located?
Precentral gyrus
What are the somatotopically organised motor maps found in area 6?
Premotor area (PMA) Supplementary motor area (SMA)
What is the function of the SMA?
Innervates distal motor units directly
What is the function of the PMA?
Connects reticulospinal neurones innervating proximal motor units
What creates a mental image of body?
Somatosensory, proprioceptive, and visual inputs to posterior parietal cortex
Where are decisions made about what actions/movements to take?
Prefrontal and parietal cortex
Where do axons from the prefrontal and parietal cortex converge?
Area 6
What happens at the area where the prefrontal and parietal cortex converge?
Signals encoding what actions are desired are converted into how the action will be carried out.
