Central Control of Movement Flashcards
What is the heirarchy of motor control?
Cortex: planning
Mid-brain- Equilibrium
Brain stem- Posture
Spinal cord- Execution
Movements
Voluntary- skilled, learned, conscious
Involuntary- postural, antigravity
What are the 2 major groups of descending pathways?
Lateral pathways and ventromedial pathways
Lateral pathways
Involved in voluntary movement of the distal musculature (limbs)
Ventromedial pathways
Involved in the control of posture and locomotion
Corticospinal tract (lateral pathway)
Controls primary motor activity for the somatic motor system from the neck to the feet
Lesion of the corticospinal tract
Inability to manipulate the lips and tongue
Deficit in fore legs (muscle weakness)
Conscious proprioeptive deficit
Spastic paralysis
Rubrospinal tract (lateral pathway)
Control of muscle tone in flexor muscle groups (important for newborns)
Lesions in the rubrospinal tract
Ataxia (precise aiming at the target)
Impairment of distal movement (impaired ability to grasp)
Reticulospinal tract (ventromedial)
Excites flexors and inhibits extensors
Helps with voluntary movement staying at equilibrium
Lesion in the reticulospinal tract
lack of anticipatory adaption
Increased reflex activity
Impaired motor movement
Abnormal posture
Vestibulospinal tract (ventromedial)
Balancing system in the ear
Works when the body is in motion
Ipsilateral
Lesion in the vestibulospinal tract
Loss of antigravity muscle tone
Postural destabilization
Vestibular ataxia
Head and body will tilt to the injured side
Descending brainstem motor pathways to the spinal cord (rubrospinal)
- Motor cortices
- Red nucleus
- Rubrospinal tract
- Lateral white matter (lateral column) and lateral part of gray matter
PNS - Distal musculature
Descending brainstem motor pathways to the spinal cord (Reticulospinal)
- Motor circles
- Reticular formation
- Reticulospinal tract
- Medial white matter (ventral column) and medial part of gray matter
PNS - Axial proximal musculature
Descending brainstem motor pathways to the spinal cord (vestibulospinal)
- Sensory organs in head
- Vestibular nuclei
- Vestibulospinal tract
- Medial white matter (ventral column) and medial part of gray matter
PNS - Axial proximal musculature
Brainstem
Motor and sensory functions for the face and head regions
What centers does the brainstem control?
Respiration, cardiovascular, GIT (partially), equilibrium and eye movements (affected by lesions in the medulla)
Central pattern generators
Produce the patterns of neural activity that underlie rhythmic motor behaviours
Generated centrally, without sensory feedback
Where does CPG control in the brainstem?
Breathing, swallowing, chewing, and certain eye movements
CPG for locomotion
Walking, trotting, cantering, scratching and paw shaking are within the spinal cord
Somatotopic map of primary motor cortex
More than 50% to the upper motor system (face)
Next is hands
Not too much to the feet, legs and toes
Cerebral cortex
Primary motor cortex (discrete purposeful movements)
Premotor area (patterns of movement)
Supplemental motor area (bilateral movements, fixation movements)
Inputs to motor cortex
Somatosensory, frontal, auditory, visual
Cerebellum and basal ganglia
