Physio Lab Quiz 3

Which of the following terms are NOT used interchangeably? in vivo - in the body/ the living muscle tension - muscle force motor unit - motor neuron muscle cell - muscle fiber

Which of the following is NOT a phase of a muscle twitch? contraction phase shortening phase latent period relaxation phase

Where does the acetylcholine that stimulates muscle contraction bind?

When acetylcholine binds to its receptors, it results in __________.

Which of the following occurs during the latent period of muscle contraction? Acetylcholine is released at the axon terminal. An action potential is generated. Acetylcholine is released at the axon terminal and an action potential is generated. Calcium is released from the sarcoplasmic reticulum.

As the stimulus voltage was increased in this activity, which of the following occurred? The muscle force generated increased. The muscle force generated decreased. The latent period increased in length. The latent period decreased in length.

Which of the following describes the relaxation phase? The sarcomeres are decreasing in length, and the force generated increases. The sarcomeres are increasing in length, and the force generated decreases. The sarcomeres are decreasing in length, and the force generated decreases. The sarcomeres are increasing in length, and the force generated increases.

Which of the following can trigger a muscle twitch? release of acetylcholine or electrical stimulation release of acetylcholine or release of calcium from the sarcolemma release of acetylcholine electrical stimulation release of calcium from the sarcolemma

Which of the following is proportional to the amount of tension produced by a skeletal muscle? the number of motor units activated the length of the latent period the threshold voltage the length of the relaxation phase

NO force is generated during which of the following? the relaxation phase the contraction phase a muscle twitch the latent period

What is the minimum voltage needed to generate active force in the skeletal muscle?

A motor unit is defined as ______

In the lab, a researcher finds that the threshold stimulus to induce an action potential in a muscle fiber's sarcolemma was 3.0 volts. Which of the following would result in muscle tension? 4.0 volts 2.0 volts 3.0 volts 3.0 volts and 4.0 volts 1.0 volt

Increasing the applied voltage in the simulation corresponds to which in vivo event? motor unit recruitment muscle twitch recruitment muscle fiber recruitment motor neuron recruitment

As the stimulus voltage increased, the resulting muscle tension _______.

Which of the following occurs during the contraction phase?

Treppe is the phenomenon that results in _______.

When the frequency of stimulation of a muscle is great enough, _______.

When wave summation occurs, _______.

Why does wave summation occur?

Which of the following produced an increase in stimulus intensity? clicking the mouse in rapid succession clicking the mouse in rapid succession and allowing the muscle to completely relax in between contractions allowing the muscle to completely relax in between contractions increasing the voltage applied

Which of the following produced an increase in stimulus frequency?

Which of the following does NOT describe tetanus? The maximum force produced has reached a plateau. It can be unfused. The muscle relaxes fully between contractions. It can be fused.

Which of the following is true of the maximum stimulus frequency? Muscle has reached maximal tetanic tension. Muscle force will decrease. No greater muscle force can be generated and the muscle has reached maximal tetanic tension. No greater muscle force can be generated and muscle force will decrease. No greater muscle force can be generated.

Which of the following does NOT describe treppe? A period of relaxation can be seen on the muscle twitch tracing. It is also referred to as the "staircase" effect. An increase in stimulus intensity is required to see the effect. An incremental increase in force occurs.

Muscle twitches overlap with _______.

Which of the following would result in fused or unfused tetanus compared to a single muscle twitch? increasing the stimulus frequency threshold stimulus and single stimuli decreasing the stimulus frequency or increasing the stimulus frequency decreasing the stimulus frequency

Which of the following describes the relationship between stimulus frequency and muscle tension? When stimulus frequency increases, muscle tension increases to a maximum value. When stimulus frequency increases, muscle tension decreases. When stimulus frequency decreases, muscle tension increases indefinitely. When stimulus frequency increases, muscle tension increases indefinitely.

At what stimulus frequency was maximal tetanic tension developed?

Which of the following occurs if the load attempted is equal to or greater than the force generated by a muscle? Isotonic muscle contraction occurs. Isometric muscle contraction occurs. The muscle shortens. The muscle lengthens.

The resting length of the muscle _______.

The graph of the length-tension relationship illustrates _______.

Which of the following is generated when cross-bridges form between actin and myosin?

Which of the following describes the relationship between length and tension?

Why does the active force of skeletal muscle change with the muscle's resting length?

Which starting length of the muscle provided the maximum total force?

At which muscle length was the passive force the greatest?

Which of the following occurs during isotonic concentric contraction?

Which of the following occurs during the latent period of isotonic concentric contraction?

The speed of muscle contraction is called the _______.

For a weight to be lifted, which of the following must occur?