L08: Disorders Of The Motor Unit Flashcards
What is a motor unit
Minimal functional unit of the motor system
What is a motor unit composed of
An alpha motor neurone
All extrafusal skeletal muscle fibres is supplies
Neuromuscular junction
How are motoneurone arranged
Into 2 neurones called upper and lower motoneurone
What does damage to upper motoneurone lead to
Upper motor neurone signs
What does damage to the lower motoneurone lead to
Lower motoneurone signs
What does innervation mean
Normal healthy statue of a nerve supply to a muscle/target
What does denervation mean
The loss of innervation of a nerve supply to its muscle/target
What does re-innervation mean
Regrets of a damaged nerve to resupply it’s muscle/target
Which component of the motor unit can become damaged to give lower motor neurone signs
Cell body of the neurone
Axon
Neuromuscular junction
Muscle
If the cell body of the lower motoneurone is damage is there a chance of re-innervation
No. The motoneurone dies
What is polio myelitis
A communicable infection that targets the cell bodies of lower motoneurones. This leads to paralysis of the muscle it supplies
What is progressive supranuclear palsy
When both the upper and lower motoneurone is killed
What is Lou Gehrig’s disease and amyotrophic lateral scelerosis
Death of the lower motoneurone
What is Gillian barre syndrome
Demyelination of axons caused by viral infections or diabetic neuropathy
What does botulinum toxin do
Deplete the pre-synaptic neurotransmitter due to non well preserved food tins
