Motor control Flashcards
3 Properties of spinal reflex
Organised neutral circuit
Contained within spinal cord
Reproducible, autonomic response to particular stimuli
What are two examples of reflexes
Stretch
Withdrawal
How is the movement of muscles monitored
Modified nerves - Dendrites of sensory neurons wrapped around central sensory region
Explain how withdrawal reflex works
Stimulus sends message to spine through dorsal root. Synapses in grey matter at multiple neurons. Sends out of spinal cord to move muscles AND up to the brain.
Why is reflex important
If we are in immediate danger it allows our muscles to react to get out out of the danger without the message having to have all the way up to the brain and back again.
Explain size of regions in motor cortex
Motor cortex has regions that control different parts of the body (on the opposite side). The more motor axons a body part has (how dexterous it needs to be) will have more area in the cortex
Describe motor unit recruitment
The more motor axons that are activated, the more muscle fibres are recruited, the stronger the movement will be.
What is a motor unit
A collection of muscles fibres, their neuron and axon
How does muscle recruitment help with prolonged tension/movement
There are many motor units within a muscle. They are all active and resting at different points so the muscle is always contracting but each unit is able to rest so it doesn’t get fatigued.
Describe how frequency affects muscle contraction
When stimulus occurs more frequently it adds twitches together to form a maximum force (tetanus)
Describe tetanus
It is when twitches are so close together they no longer have time to rest and form a smooth sustained force.
What does the cerebellum do in Preparing and performing movements (somatic - voluntary)
Co-ordinating muscles, with sensory feedback
Maintains posture and gaze
Helps learn and automate movements
Gets feed back from body about how movement is going (monitors balance and equilibrium)
Where does the cerebellum report back to
Signals adjustments to primary motor cortex
What kind of feedback does the cerebellum receive
muscle spindles (how stretched) Limb and body motion and position
