26-5-2021 PhysioEx Exercise 2 Activity 2
PhysioEx Lab Report
Exercise 2: Skeletal Muscle Physiology
Activity 2: The Effect of Stimulus Voltage on Skeletal Muscle Contraction
Name:
Date:
Session ID:
Pre-lab Quiz Results
You scored 100% by answering 4 out of 4 questions correctly. 1
Skeletal muscle fibers are innervated (stimulated) by
You correctly answered: motor neurons.
2 A single action potential propagating down a motor axon results in
You correctly answered: a single action potential and a single contractile event in the muscle fibers it
innervates.
3 In resting skeletal muscle, calcium is stored in
You correctly answered: the sarcoplasmic reticulum.
4 During the latent period for an isometric contraction
You correctly answered: the cellular events involved in excitation-contraction coupling occur.
Experiment Results
Predict Question
1 Predict Question: As the stimulus voltage is increased from 1.0 volt up to 10 volts, what will happen
to the amount of active force generated with each stimulus?
Your answer: The active force will first increase and then plateau at some maximal value as the
stimulus voltage increases.
Stop & Think Questions
1 What do you observe in the active force display when the stimulus voltage is set to 0.0, and why
does this observation make sense?
You correctly answered: 0.00; there was no activation of skeletal muscle fibers by this stimulus.
2 What is the lowest stimulus voltage that induces active force in the skeletal muscle?
You correctly answered: threshold voltage.
3 Enter the threshold voltage for this experiment.
https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex2/act2/ 1/11
, 26-5-2021 PhysioEx Exercise 2 Activity 2
You answered: 0.8 volts.
4 Enter the maximal voltage for this experiment.
You answered: 10 volts.
Experiment Data
Voltage (v) Length (mm) Active Force Passive Force Total Force
0.0 75 0.00 0.00 0.00
0.2 75 0.00 0.00 0.00
0.8 75 0.02 0.00 0.02
1.0 75 0.15 0.00 0.15
1.5 75 0.43 0.00 0.43
2.0 75 0.66 0.00 0.66
2.5 75 0.87 0.00 0.87
3.0 75 1.04 0.00 1.04
3.5 75 1.19 0.00 1.19
4.0 75 1.32 0.00 1.32
4.5 75 1.42 0.00 1.42
5.0 75 1.51 0.00 1.51
5.5 75 1.59 0.00 1.59
6.0 75 1.65 0.00 1.65
6.5 75 1.70 0.00 1.70
7.0 75 1.74 0.00 1.74
7.5 75 1.78 0.00 1.78
8.0 75 1.81 0.00 1.81
8.5 75 1.82 0.00 1.82
9.0 75 1.82 0.00 1.82
9.5 75 1.82 0.00 1.82
10.0 75 1.82 0.00 1.82
Voltage = 0.0 V
https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex2/act2/ 2/11
PhysioEx Lab Report
Exercise 2: Skeletal Muscle Physiology
Activity 2: The Effect of Stimulus Voltage on Skeletal Muscle Contraction
Name:
Date:
Session ID:
Pre-lab Quiz Results
You scored 100% by answering 4 out of 4 questions correctly. 1
Skeletal muscle fibers are innervated (stimulated) by
You correctly answered: motor neurons.
2 A single action potential propagating down a motor axon results in
You correctly answered: a single action potential and a single contractile event in the muscle fibers it
innervates.
3 In resting skeletal muscle, calcium is stored in
You correctly answered: the sarcoplasmic reticulum.
4 During the latent period for an isometric contraction
You correctly answered: the cellular events involved in excitation-contraction coupling occur.
Experiment Results
Predict Question
1 Predict Question: As the stimulus voltage is increased from 1.0 volt up to 10 volts, what will happen
to the amount of active force generated with each stimulus?
Your answer: The active force will first increase and then plateau at some maximal value as the
stimulus voltage increases.
Stop & Think Questions
1 What do you observe in the active force display when the stimulus voltage is set to 0.0, and why
does this observation make sense?
You correctly answered: 0.00; there was no activation of skeletal muscle fibers by this stimulus.
2 What is the lowest stimulus voltage that induces active force in the skeletal muscle?
You correctly answered: threshold voltage.
3 Enter the threshold voltage for this experiment.
https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex2/act2/ 1/11
, 26-5-2021 PhysioEx Exercise 2 Activity 2
You answered: 0.8 volts.
4 Enter the maximal voltage for this experiment.
You answered: 10 volts.
Experiment Data
Voltage (v) Length (mm) Active Force Passive Force Total Force
0.0 75 0.00 0.00 0.00
0.2 75 0.00 0.00 0.00
0.8 75 0.02 0.00 0.02
1.0 75 0.15 0.00 0.15
1.5 75 0.43 0.00 0.43
2.0 75 0.66 0.00 0.66
2.5 75 0.87 0.00 0.87
3.0 75 1.04 0.00 1.04
3.5 75 1.19 0.00 1.19
4.0 75 1.32 0.00 1.32
4.5 75 1.42 0.00 1.42
5.0 75 1.51 0.00 1.51
5.5 75 1.59 0.00 1.59
6.0 75 1.65 0.00 1.65
6.5 75 1.70 0.00 1.70
7.0 75 1.74 0.00 1.74
7.5 75 1.78 0.00 1.78
8.0 75 1.81 0.00 1.81
8.5 75 1.82 0.00 1.82
9.0 75 1.82 0.00 1.82
9.5 75 1.82 0.00 1.82
10.0 75 1.82 0.00 1.82
Voltage = 0.0 V
https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex2/act2/ 2/11
