Pathways Flashcards
Pathways
There are MANY complex motor pathways. Two major ones are…
Cortico-Spinal (“Pyramidal”) Tracts
Ventro-Medial Tracts
- These pathways are primarily Ipsi-lateral, (though some collaterals crossover in Brain Stem)
- Primarily controls posture, movement of neck, shoulders & trunk, esp in co-ord with sensory activity
(e. g. head/eye movement) & gross body movement (walking) – Note all involve both sides at once
Cortico-Spinal (“Pyramidal”) Tracts
mainly to Contra-Lateral Periphery, crossover at Pyramids of Medulla
- Large Pyramid Cells
- Fast, myelinated tracts,
Large Pyramid Cells
from Motor Cortex, synapse in Spinal Cord (onto Inter-Neurons or Motor Neurons)
- Some synapse first at Red Nucleus (e.g. integrate w/Vestibular & Cerebellar info) then most to Cord
Red Nucleus
(e.g. integrate w/Vestibular & Cerebellar info)
Fast, myelinated tracts,
esp. for precise control of peripheral movements (e.g. hands, fingers, limbs, + face)
Ventro-Medial Tracts
Mainly for Bi-Lateral Midline control
- Multiple sub-paths,
- Many make multiple connections in Tectum, Vestibular Nucleus, Reticular Formation, then to Cord
Bi-Lateral Midline control
(both sides of central body & co-ord’d limbs)
Multiple sub-paths
originating from sub-cortex, most synapse in Spinal Cord, esp on Inter-Neurons
—Many make multiple connections in Tectum, Vestibular Nucleus, Reticular Formation, then to Cord