Soc-14

Question 1

Muscle fibres

Answer 1

Skeletal muscle is made up of bundles of individual muscle fibers called myocytes. Each myocyte contains many myofibrils, which are strands of proteins that can grab on to each other and pull. This shortens the muscle and causes muscle contraction.

Question 2

Type 1

Answer 2

Type I muscle fibers are more efficient over long periods of time. They are mainly used for postural maintenance (such has holding the head upright), or endurance exercises (like marathon running).

Question 3

Type 2a

Answer 3

Type 2a muscle fibres are known as fast twitch oxidative fibres. These fibres generate a lot more force than slow twitch fibres but are a little bit more prone to fatigue. Fast twitch 2a fibres contract quickly to generate short bursts of explosive speed.

Question 4

Type 2x

Answer 4

Fast twitch muscle fibres used in anaerobic work and can generate much greater force than other fibre types,but fatigue quickly.

Question 5

Myoglobin

Answer 5

A red pigment that transports oxygen to the muscles.