Skeletal Muscle Contraction: Mechanisms and Responses

True

The voltage at which the first noticeable contractile response is obtained is called the threshold stimulus.

• True

Tetanus

A muscle contraction that is smooth and sustained as a result of high-frequency stimulation is tetanus.

Oxygen deficit in the tissue after prolonged activity

Muscle fatigue, the loss of the ability to contract, may be a result of:

• Oxygen deficit in the tissue after prolonged activity

20 volts

According to the data, what is the threshold stimulus (threshold voltage)?

• 20 volts

80 volts

According to the data, what is the maximal stimulus (maximal voltage)?

• 80 volts

6 sec

At which time does summation take effect?

• 6 sec

tetanus

Which term best describes the event after Time = 8.225 sec?

• tetanus

isometric

A muscle contraction in which the length of the muscle remains constant during the time that the force is applied to the load is isometric.

the length of the muscle changes.

An isotonic contraction of a muscle is one in which:

• the length of the muscle changes.

1.5 g

Which of the weights induced the longest latent period of the muscle contraction?

• 1.5 g

2.0 g

Which weight was not lifted by the muscle?

• 2.0 g

the initial velocity to move the weight decreases

As the weight of the load increases:

• the initial velocity to move the weight decreases

T-Tubules

This

Motor End Plate

Where the axon terminal of the neuron meets this specialized region of the muscle fiber’s plasma membrane.

Neuromuscular Junction

The Motor neuron & a muscle fiber intersect at the neuromuscular junction.

…

The action potential in a motor neuron triggers the release of acetylcholine from the terminal.

C) Latent period

What is the period of time that elapses between the generation of an action potential and the start of muscle tension development in a muscle fiber?

• C) Latent period