click below
click below
Normal Size Small Size show me how
A2 AQA PE Muscles
AQA A2 PE muscles
Term | Definition |
---|---|
Actin | The thin protein filament found in muscle cells that together with myosin form sarcomeres, the contractile units of skeletal muscle |
Adenosine triphosphate (ATP) | A high energy compound found in all muscle cells which is broken down to release energy for all purposes |
All or none law | If a motor impulse is of sufficient intensity, the motor unit is stimulated and all the muscle fibres within it will contract to their maximum possible extent |
Fasciculi | Bundles of muscle fibres that make up the muscle belly |
Fast oxidative glycolytic (FOG) muscle fibres (type 2a) | Fast twitch muscle fibres that pick up certain slow twitch characteristics so that they can withstand fatigue for longer |
Fast twitch muscle fibre | A type of muscle fibre that has a high glycolytic capacity (anaerobic). It is associated. With speed and power based activities |
Myosin cross bridge | The arm and head of the myosin filament which extends to bind on to the actin filament |
Tropomyosin | Threadlike spirals that wrap around the actin filament which covers the myosin binding site which prevents myosin attachment during the relaxed state |
Epimysium, perimysium, endomysium | Connective tissue that surrounds the muscle belly, fasciculi and muscle fibres respectively |
Motor unit | The motor nerve and the group of muscle fibres that it controls |
Myoglobin | A protein in muscle cells that stores and transports oxygen |
Myosin | The thick protein filament that together with actin form sarcomeres, the contractile units of skeletal muscle |
Sarcomere | The contractile units of skeletal muscle. They are composed of two myofilaments, actin and myosin |
Slow twitch muscle fibre | A type of muscle fibre that uses oxygen to produce energy |
Spatial summation | Controlling strength of muscle contraction; more motor units, larger motor unit, fast twtich motor units |
Troponin | A calcium receptor that sits on top of tropomyosin. In the presence of calcium it pulls tropomyosin away from the myosin binding site and allows myosin to bind to the actin filament and the sliding filament mechanism to commence |
Calcium | Has to be released to allow mysocin to attach to tropomyosin |