Neural Control of Movement Flashcards
What 4 areas underlie lower motor neurone weakess?
Within muscle spindle, at motor end plate, at spinal nerve and at axon projection from the ventral root
What are the basal ganglia?
Group of structures linked to the thalamus in the base of the brain that are involved in coordination of movement
What are the symptoms of cerebellum damage?
Ataxia and hypotonia
Define ataxia
The loss of full control of bodily movements
What are the symptoms of damage to the basal ganglia?
Slowing or unwanted movements (hyper/hypokinesia)
What are the symptoms of damage to the association motor cortex?
Apraxia (unable to execute familiar learned movement in the absence of sensorimotor function)
What are the symptoms of damage to the descending motor pathways?
Spasticity and hypertonia
Define spasticity
Increase in muscle tone due to loss of inhibition of gamma motor neurones
Define clonus
Muscular spasm involving repeated, often rhythmic, contractions
What is a neuromuscular disorder?
This is a condition affecting one or more of the following: muscles, nerves, NMJ, motor/sensory cell-body
What is muscle rigidity?
An increase in muscle tone due to the loss of inhibition of alpha motor neurones
What is flaccidity (hypotonia)?
Occurs when the nerve or the LMNs are damaged
What is the role of lower motor neurones?
Produce muscle contractions via motor units (strength is related to motor units)
What is the role of upper motor neurones?
Produce voluntary movements
What is the role of the cerebellum?
Coordinates muscle movement and selects correct sequences
What is the role of basal ganglia?
Involved in the initiation and maintenance of movements and contains motor programmes
What is the role of the association motor cortex and basal ganglia in the control of voluntary movement?
Strategy: planning and selecting programmes to produce desired movement
What is the role of the primary motor cortex and cerebellum in the control of voluntary movement?
Tactics: sequences of muscle contractions over time to produce smooth, accurate movements
What is the role of the brainstem and spinal cord in the control of voluntary movement?
Execution: of voluntary movement and any needed postural adjustment
What is the function of the cerebrospinal tract?
Involved in precise movements
What is the function of the rubrospinal tract?
Involved in gross movements and facilitates flexor movement
What is the function of the vestibulospinal and reticulospinal tracts?
Involved in posture and balance
What is an ‘efference copy’ produced by upper motor neurones?
A copy of the movement-producing signal being produced and collated with the sensory input which results from the patient’s movement, enabling a comparison of actual movement with desired movement
What is the general function of the cerebellum?
The cerebellum coordinates complicated multi-joint movements and acts as a comparator or predictor of movements as it receives direct input from muscles and compares it with the intended signal for movement from the motor cortex
What are three main parts of the cerebellum?
Vestibulocerebellum, spinocerebellum and cerebrocerebellum
What is the role of the vestibulocerebellum
Involved in balance and posture (eye movements, VOR)
What is the role of the spinocerebellum?
Involved in locomotion (voluntary movements of arms and legs)
What is the role of the cerebrocerebellum?
Involved in skilled motor tasks (speech, hand-eye coordination and cognitive eye movements)
What are the five nuclei in the basal ganglia?
Caudate, putamen, globus pallidus, substantia nigra and subthalamic nuclei
What is the role of the posterior parietal cortex in movement?
Involved in the decision to move and the functional consequence of action
What is the role of the association motor cortex in movement?
Stores plans to move until they are required; premotor holds external cues and supplementary motor holds internal cues
What is the role of the primary motor cortex in movement?
Involved in the instruction to move via activation of the descending pathways
