Question

The strength of contraction of an entire skeletal muscle is dependent on the:

• A. Number of muscle fibres that contract simultaneously
• B. Frequency of contraction of each muscle fibre
• C. Number of active cross bridges in each muscle fibre
• D. All the above

Answer 1

The correct option is D All the above

Motor unit recruitment is a measure of how many motor neurons are activated in a particular muscle. It is therefore a measure of how many muscle fibres of that muscle are activated. The higher the recruitment, the stronger the muscle contraction will be.
Force of muscle contraction depends upon muscle fibre summations and frequency summations. So, more the number of muscle fibres and more is the frequency of contraction, more will be the muscle contraction. More the number of cross bridges are formed, more will be the strength of the muscle contraction.
So, all the given options are correct.