Question

1.While the biceps is contracting, there is no activity in the triceps. True or false

2.As contractile strength increases, ____________ muscle motor units become involved in the contraction. More or ess

3.A maximum strength skeletal muscle contraction can be sustained indefinitely. True or false

Answer 1

True.

During a muscle contraction The agonist muscle contracts,while the antagonist muscle relaxes.

For example-

a.Flexion or bending of elbow- biceps contracts & triceps relaxes.

b.Extension or straightening of elbow, -triceps contract & biceps relax.

2. As contractile strength increases, more muscle motor units become involved in the contraction.

As the strength of contraction increases-- Motor unit recruitment occurs--That is activation of additional motor units which leads to an increase in contractile strength in a muscle.

A motor unit refers to 1 motor neuron & all muscle fibers stimulated by it.

3.False

Twitch summation occur by stimulating the muscle before it has relax completely which results in Greater Tension.

Tetanus or sustained contraction Occur when repeating the stimulation before the muscle has a chance to relax at all.

A single maximum strength skeletal muscle contraction cannot be sustained indefinitely