Neuromuscular system Flashcards
What is the function of SO ( type 1) muscle fibres?
They are designed to store oxygen in myoglobin and process it in the mitochondria. This allows aerobic work to take place.
what is the function of the FG and FOG ( type 2a and 2x ) muscle fibres ?
They are designed to work under anaerobic intensities with large stores of phosphocreatine used for rapid energy production. However fatigue is quick and it can only be used for a short period of time.
What is the role of muscle spindles and what do they do during PNF stretching ?
Muscle spindle fibres are stretch receptors that detect a change in length of the muscle tissue. During PNF , they initiate a stretch reflex muscle contraction which helps prevent over stretching
What is the role of the golgi tendon organs?
Golgi tendon organs detect the tension that the muscle is exerting . It also has inhibitory effects which means that it sends inhibitory signals causing it to relax to prevent injury
What happens during PNF stretching ?
The muscle is contracted isometrically for at least a period of 10 seconds it then relaxes and is stretched again usually going further the second time.
What is a motor unit ?
A motor unit includes motor neurone and muscle fibres and it is responsible for processing information and sending impulses down the axon
What is wave summation ?
When there is a repeated nerve stimulation without time to relax sustaining muscle contraction the rate of stimuli delivery decreases which causes less time for the muscles to relax )
What is Tetanus/ tetanic contraction ?
It happens after server stimuli which causes sustained muscle contraction due to repeating fast stimuli. If the stimuli is delivered at a high frequency without rest the twitches overlap
What is spatial summation ?
It’s all the motor units that are stimulated at exactly the same time then maximum force that can be applied.
What is the all or nothing law ?
That there is a minimum amount of stimulation required to start a muscle contraction if the impulse is strong enough then all muscle fibres will contract but if the impulse is less then threshold required no muscle action will occur.
