Muscular system

Question 1

What are the 3 roles of a muscle?

Answer 1

Agonist, antagonist or fixator

Question 2

Describe muscle fibre composition and explain how muscle contractions occur

Answer 2

Fibres contain two types of filament, thin actin filaments and thicker myosin filaments. During contraction the myosin filaments grab on to the thinner actin filaments forming cross bridges and allowing the fibre to contract (shorten). The more cross bridges the stronger the force of contraction.

Question 3

What is the difference between isotonic and isometric contractions

Answer 3

Isotonic contractions involve the muscle fibres shortening( concentric) or lengthening (eccentric) to produce movement. Eg bicep curl
Isometric contractions do not involve movement and the muscles fibres do not change length eg plank