Topic 6: Nervous System 6 - Motor Output - SNS Levels of motor control Flashcards
Levels of motor control diagram
What occurs in level one, planning? (3)
- plans sequence of muscle contractions
- signals primary motor cortex
- works with input from cerebellum
What questions should you ask for level one?
do you want to move?
if yes. what movement needed?
Which muscles need to contract?
What occurs in level 2?
- signals directly to lower motor neurons via corticospinal tract for fine skilled movements
What is the pathway for level 3?
brainstem nuclei to descending motor tracts to lower motor neurons (indirect tracts)
What occurs in level 3? (2)
- receives input from cortex, basal nuclei, cerebellum
- involved in co-ordination of large muscle groups for maintenance of posture and locomotion
What structures does level 4 include? (2)
- spinal cord
- contains cell bodies of lower motor neurons
What occurs in level 4?
- network of neurons (central pattern generators, CPGs) which set rhythmic, repeated movements (walking, running)
What does level 4 require?
- cortical signals to begin or stop movement
How does the cerebellum play a role in planning and initiating movement? (3)
send input to cortical areas
- stores planned movement and compares actual to plan, using sensory input from ex. proprioceptors
- corrects if necessary
What is the function of the cerebellum? (2)
- maintains balance, controls eye movements, and role in maintaining muscle tone (low level of contraction)
- coordinates skilled voluntary muscle movements and timing of contractions involving more than 1 joint
What is the corticospinal (direct) pathway?
- cortex to skeletal muscle
What are the 2 parts to the corticospinal pathway?
- Upper and Lower motor neurons
What are upper motor neurons? (2)
- cell bodies in primary motor cortex
- axons down spinal cord
What are lower motor neurons?
- cell bodies in ventral horn of spinal cord
- axons exit via spinal nerves
