P4, M1 and D1 Essay

Words: 1102
Pages: 5

P4 - Describe the function of the muscular system and the different fibre types

M1 – Explain the function of the muscular system and the different fibre types

D1 – Analyse the function of the muscular system and the different fibre types

Antagonistic Pairs

Antagonistic Pairs are a pair of muscles working together to allow coordinated movement of the skeletal joints. Muscles can only exert a force and do work by contracting. An example is the antagonistic pair of muscles used in bending and straightening the arm. To bend the arm requires the biceps to contract, while the triceps relax. If the arm is to be straightened, the reverse happens. The individual components of antagonistic pairs can be classified into extensors and
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Long distance runners will have a very high amount of slow twitch fibres in their muscles, making them more resistant to fatigue.

Type 2a

These fibres use both aerobic and anaerobic pathways almost equally to create energy. They contract rapidly, are twice as thick as type 1 fibres and are quick to fatigue. They have a poor blood supply, are whiter in appearance, due to the lack of oxygen. Type 2a fibres are best suited to team sport activities, or sports that are too long to be type 2b fibres and too short to be type 1 fibres, for example sports like the 400m. An example of when the fibres will be working the most is probably the last 100 metres when the athlete is trying to build up more speed. This means the fibres have to work harder in order for the legs to move faster so they can pick up speed. These types of fibres have both medium aerobic and anaerobic capacity, making them ideal for this type of event. They are less resistant to fatigue than type 1 fibres, but are more resistant than type 2b fibres, again making them perfect for the 400m, lasting just long enough for the race. The 400m also requires a good anaerobic capacity for the final 100m and these fibres provide a good level of capacity, making it great for this type of event. Type 2a fibres give a mixture of slow and fast muscle contractions, making this useful in team sports like football as the pace of the game is constantly changing.

Type 2b

These are the