Chapter 1.3 (The Neuromuscular System) Flashcards
Define Aerobic
Literally means ‘with oxygen’ so refers to low to medium intensity exercise where the demand for oxygen can be met
Define Anaerobic
Means ‘without oxygen’ and refers to exercise at high intensity such as sprinting, where the demand for oxygen is so high it cannot be met
What are the 3 muscle fibre types?
- Slow oxidative (type I) (also known as slow twitch)
- Fast oxidative glycolytic (type IIa)
Fast glycolytic (type IIb)
What are the characteristics of slow twitch muscle fibres?
- Slower contraction speed
- Better adapted to lower intensity exercise
- Produce most of their energy aerobically
What are the characteristics of fast twitch muscle fibres?
- Faster contraction speed
- Generate a greater force of contraction
- Used for short, intense bursts of energy
- Produce most of their energy anaerobically
Define Hypertrophy
Where the muscle has become bigger and stronger
What is a Motor Unit?
A motor neurone and its muscle fibres
What are motor neurones?
Nerve cells which transmit the brains instructions as electrical impulses to the muscles
What are neuromuscular junctions?
Where the motor neurone and the muscle fibre meet
Define the All or None law
Where a sequence of impulses has to be of sufficient intensity to stimulate all of the muscle fibres in a motor unit in order for them to contract. If not, none of them contract
Define Wave Summation
Where there is a repeated nerve impulse with no time to relax so a smooth, sustained contraction occurs, rather than twitches
Define Tetanic Contraction
A sustained muscle contraction caused by a series of fast repeated stimuli
Define Spatial Summation
When the strength of a contraction changes by altering the number and size of the muscles motor units
What are muscle spindles?
These detect how far and how fast and muscle is being stretched and produce the stretch reflex
What are Golgi tendon organs?
These are activated when there is tension in a muscle
