Exam 14: Skeletal Muscle Physiology: Frogs and Human Subjects

In the glycerinated muscle, these substances are necessary for maximal contraction to occur.

From your own experience, predict the relative times to fatigue of a subject's upper limb muscles as they hold a light book or a very heavy book in front of them.

The stimulus from motor neuron to neuromuscular junction is , and the stimulus from axon terminal to muscle sarcolemma is _ .

This ion is critical for normal excitation-contraction coupling, but is not necessary for contraction of the glycerinated muscle fibers you worked with in the lab.

During this period of muscle twitch, there is no change in tension in the muscle.

A muscle twitch is _.

Which event requires multiple stimuli?

According to its definition, muscle fatigue is .

When the nerve to a muscle is destroyed, _.

The maximum force that can be attained by a contracting muscle occurs during .

At this stimulus strength, all muscle cells of a particular muscle are being stimulated.

The gradual activation of more and more motor units is called .

The rising phase of a muscle twitch represents .

An electromyogram is .

An electromyogram measures .

When muscle is stimulated directly to contract, does the rising phase of the twitch begin immediately? If not, why not?

An action potential is .

Most subjects use their dominant forearm far more than their nondominant forearm. How might the dominant forearm differ physiologically or structurally from the nondominant forearm?

Graded muscle contractions .

What causes muscle contractions to be graded?