Name: Jennifer Broussard Exercise 2: Skeletal Muscle Physiology: Activity 2: The Effect of Stimulus Voltage on Skeletal Muscle Contraction Lab Report 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: c. motor neurons. 2. A single action potential propagating down a motor axon results in You correctly answered: d. 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: c. the sarcoplasmic reticulum. 4. During the latent period for an isometric contraction You correctly answered: c. the cellular events involved in excitation-contraction coupling occur.

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Experiment Results Predict Question: 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 : c. The active force will first increase and then plateau at some maximal value as the stimulus voltage increases. Stop & Think Questions: What do you see in the active force display when the stimulus voltage is set to 0.0, and why does this observation make sense? You did not answer this question. Correct answer: a. 0.00 g; there was no activation of skeletal muscle fibers by this stimulus. What is the lowest stimulus voltage that induces active force in the skeletal muscle? You did not answer this question. Correct answer: b. threshold voltage 6. Enter the threshold voltage for this experiment in the field below and then click Submit Data to record your answer in the lab report You answered: 8.1 volts 12. Enter the maximal voltage for this experiment in the field below and then click Submit Data to record your answer in the lab report. You answered: 7.5 volts