The all-or-nothing principle in muscle contraction states that a muscle fiber fully contracts or does not contract at all, with the force determined by the number of fibers contracting. Option d is the correct option.
The all-or-nothing principle best describes how a muscle fiber contracts. This principle states that a muscle fiber will either contract fully or it will not contract at all. The amount of force generated by a muscle is determined by the number of muscle fibers that are contracting simultaneously; more fibers contracting results in greater force. The length-tension relationship also plays a crucial role as it determines the optimal overlap between thick and thin filaments within a sarcomere for maximum muscle power. In addition, the nervous system control involves recruitment, which is the process of activating more motor units to produce stronger muscle contractions. Option d is the correct option.
The appropriate question is :
what best describes the all-or-nothing principle?
a) all muscle fibers contract, or none at all do.
b) the switch from type iia to type iix muscle fibers a motor unit will either contract maximally or not at all.
c) the switch from type i to type ii muscle fibre
d) a muscle fiber fully contracts or does not contract at all