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Student instructions: Follow the step-by-step instructions for this exercise found in your lab manual and record your answers in the spaces below. Submit this completed document by the assignment due date found in the Syllabus.
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ACTIVITY 1: The Muscle Twitch and the Latent Period Answers
1. The latent period of the skeletal muscle that was tested in this lab simulation was
a. about 1 second.
b. less than 1 msec.
c. between 2-3 msec.
d. variable, depending on the voltage that was applied to it.
2. True or False: Another name for a muscle cell is “myofibril.”
3. The largest active force that could be generated in the muscle is Activity 1 was _______ grams.
4. Define the terms skeletal muscle fiber, motor unit, skeletal muscle twitch, electrical stimulus, and latent period.
5. What is the role of acetylcholine (ACh) in a skeletal muscle contraction?
6. Describe the process of excitation-contraction coupling in skeletal muscle fibers.
7. Describe the three phases of a skeletal muscle twitch.
8. Does the duration of the latent period change with different stimulus voltages?
9. At the threshold stimulus, do sodium ions start to move into or out of the cell to bring about the membrane depolarization?
ACTIVITY 2: The Effect of Stimulus Voltage on Skeletal Muscle Contraction
10. The threshold voltage for the muscle in this lab simulation was ________ volts. When that voltage was used to stimulate the muscle, ________ grams of active force were generated.
11. True or False: In a resting skeletal muscle cell, most of the calcium ions freely move through the cytoplasm of the cell.