Control of Movement Flashcards
What is a motoneurone?
A single neuron which innervates all fibres in a muscle
What are the three types of alpha motoneurones?
Type 1 - slow
Type 2A - fast fatigue resistant
Type 2B - fast fatiguable
What are gamma motor neurons?
Innervate gamma muscle cells
Regulate sensitivity of muscle spindles
What are the steps in a neural reflex?
See notes
Name 4 spinal reflexes
Stretch reflex
Golgi tendon reflex
Crossed extensor reflex
Withdrawal reflex
What sensory fibre is involved in the stretch reflex, and whith what does it synapse?
1a afferent
Monosynaptic excitation of motoneurons (same and agonist muscles)
How long does the stretch reflex take?
20-40ms
What is the purpose of the stretch reflex?
Prevents tendon from over-stretch by compensating with muscle contraction
What is the purpose of the golgi tendon reflex?
Inverse of stretch reflex - causes relaxation before tendon tension can cause damage
What sensory neuron is involved in the golgi tendon reflex?
Ib
What is the difference between monosynaptic and polysynaptic reflexes?
Polysynaptic interneurons control multiple muscle groups, maybe multiple spinal segments
What is an example of a polysynaptic reflex?
Withdrawal reflex
What is a crossed extensor reflex?
One leg pulls up, the other straightens
What is clonus?
Hyperactive stretch reflex leading to spasticity
What do mirror neurons do?
Fire when observing and when doing something
