Cortical Control of Movement
The Brodmann area that serves as the primary motor cortex
What is Area 4?
The pathway originating in the superior colliculus that controls head and neck posture
What is the tectospinal tract?
The structure that receives cortical input and begins the basal ganglia motor loop
What is the striatum?
The three functional divisions of the cerebellum
What are the vestibulocerebellum, spinocerebellum, and pontocerebellum?
The difference in target between upper and lower motor neurons
What is: upper → spinal cord, lower → skeletal muscle?
The large pyramidal neurons that send axons down the corticospinal tract
What are Betz cells?
The pathway that facilitates antigravity muscles and helps maintain upright stance
What is the vestibulospinal tract?
The tonically active structure that inhibits the thalamus in the resting state
What is the globus pallidus (internal segment)?
The four deep cerebellar nuclei and the cerebellar divisions they are associated with
What are: Dentate nucleus – pontocerebellum (motor planning), Globose & Emboliform nuclei (interposed nuclei) – spinocerebellum (motor execution), Fastigial nucleus – vestibulocerebellum (balance and posture)?
The reflex that compensates by activating extensors on the opposite limb
What is the crossed extensor reflex?
The cortical area responsible for movement planning and coordination (Area 6)
What are the premotor and supplementary motor areas?
The general role of the ventromedial pathways in motor control
What are posture, balance, and locomotion control?
The neurodegenerative disease that reduces dopaminergic input to the striatum
What is Parkinson’s disease?
The cerebellar input fibers that synapse on granule cells and Purkinje dendrites
What are mossy and climbing fibers?
The artery that perfuses M1 and PMA/SMA regions
What is the middle cerebral artery?
The path taken by motor signals from cortex to spinal cord, including the point of decussation
What is the corticospinal tract (internal capsule → cerebral peduncle → pyramids → spinal cord)?
The lateral motor pathways, their functions, and where they originate
What are the corticospinal tract (originates in M1, crosses at pyramidal decussation; controls skilled voluntary movement of distal muscles) and rubrospinal tract (originates in red nucleus, crosses in pons; assists with distal flexor control and compensates for corticospinal loss)?
The pathway that inhibits unwanted movement through the subthalamic nucleus and increased thalamic inhibition
What is the indirect pathway? (cortex → striatum → globus pallidus external segment → subthalamic nucleus → globus pallidus internal segment → thalamus → cortex)
The only output neurons of the cerebellar cortex
What are Purkinje cells?
The disease associated with degeneration of striatal neurons and chorea
What is Huntington’s disease?
The lower motor neurons that cause muscle contraction, and the ones that maintain spindle sensitivity during contraction
What are alpha motor neurons (cause contraction) and gamma motor neurons (tighten intrafusal fibers to maintain A-alpha sensory feedback)?
The names, functions, and points of origin of the ventromedial pathways
What are the tectospinal tract (originates in superior colliculus; controls head and neck posture), vestibulospinal tract (originates in vestibular nuclei; facilitates antigravity muscles for balance), and reticulospinal tracts: pontine (enhances antigravity reflexes, from pons) and medullary (inhibits antigravity muscles, from medulla)?
The circuit: cerebral cortex → caudate/putamen of striatum → inhibits internal segment of globus pallidus → disinhibits VLo of thalamus → area 6 → facilitates movement
What is the direct pathway of the basal ganglia?
The cerebellar divisions, their responsibilities, and the deep nuclei they project through
What are the 1) Pontocerebellum (cerebrocerebellum) – motor planning via the dentate nucleus → premotor cortex (area 6); 2) Spinocerebellum – motor execution and coordination via interposed nuclei (globose & emboliform) → motor cortex; 3) Vestibulocerebellum – balance and eye movements via the fastigial nucleus → vestibular nuclei?
The specific anatomical areas of the cerebellum associated with each functional division
What are: Vestibulocerebellum – flocculus and nodulus; Spinocerebellum – vermis and paravermal (intermediate) zone; Pontocerebellum (cerebrocerebellum) – lateral hemispheres of the cerebellar cortex?