Muscle Fibres, Motor Units, PNF & Joints/Planes/Axis REVISION

Which muscle fibre type uses oxygen as a main source of energy?

• Fast Twitch (Type IIx

• Fast Twitch (Type IIa)

• Slow Twitch (Type 1)

• Slow Twitch (Type IIx)

Match the following

• Type IIa

• Have a slower contraction speed

• Type IIa

• used for events where longer burst of energy is needed e.g. 400m run

• Type 1

• Produces energy aerobically

• Type IIx

• high force and quick fatigability

• Type 1

• Also known as fast oxidative glycolytic fibres

Which muscle fibre type is usually large and white due to low capilliary density?

• Fast Glycolytic Fibres

• Fast Oxidative Glycolytic

• Slow Oxidative

• Fast Oxidative

A motor unit usually consists of.....

What is the all or none law?

• When there is no time for the muscle to relax

• When the strength of contraction alters

• All motor units within a muscle must be stimulated together, single motor units can not be stimulated

• All muscle fibres in a motor unit will contract maximally and simultaneously once stimulated by the motor neurone

Match the following

• Where there is repeated nerve impulse with no time for the muscle to relax

• Wave Summation

• When the strength of a contraction changes by altering the number and size of the motor units

• Motor Neurones

• Where motor neurone and muscle fibre meet

• Spatial Summation

• Nerve cells which transmit the brain's instructions as electrical impulses to the muscles

• Motor Unit

• A motor neurone and its muscle fibres

• Neuromuscular junction

A tetanic contraction is a sustained muscle contraction caused by ________ stimuli with no time for the muscle to relax

What is meant by 'threshold'?

• The maximum capacity of a muscle fibre

• The strength of stimuli that must be reached for a muscle to contract

• The number of times a motor unit can contract

• When fatigue sets in

Muscle spindles and Golgi tendon organs are both types of what?

which type of proprioceptor is responsible for detecting how far and fast a muscle is being stretched?

• CNS

• GTOs

• Muscle Spindles

• Tendons