# Physioex 8.0 Exersise 2 Skeletal Muscle Pysiology

Topics: Muscular system, Muscle contraction, Smooth muscle Pages: 2 (690 words) Published: July 7, 2011
Virtual lab 9

Activity 2: Determining the Latent Period
1. How long is the latent period? 2.78 msec.
2. What occurs in the muscle during this apparent lack of activity? Ca++ is being released from the sacroplasmic reticulum and filament movement is taking up slack. Activity 3: Investigating Graded Muscle Response to Increased Stimulus Intensity 1. Use your graph to answer and note that the dot in the graph turns red when you select that line in the table. What is the minimal, or threshold, stimulus? 0V. 2. What is the maximal stimulus? 10V.

3. How can you explain the increase in force that you observe? the increase is how many volts went into the muscle. Activity 4: Investigating Treppe
1. What happens to force production with each subsequent stimulus? It gets higher. Activity 5: Investigating Wave Summation
1. Is the peak force produced in the second contraction greater than that produced by the first stimulus? yes 2. Is the total force production even greater?yes.
3. In order to produce smooth, sustained muscle contraction at Active Force = 2 gms, do you think you will need to increase or decrease the voltage? State your hypothesis.decrease. 4. Test your hypothesis. At what voltage were you able to achieve Active Force = 2 gms? 2V. 5. How does the frequency of stimulation affect the amount of force generated by the muscle? Hint: Compare the force generated from a single click and from rapidly clicking Single Stimulus several times. It gets greater with each time.

Activity 6: Investigating Fusion Frequency / Tetanus
1. Describe the appearance of the tracing. It gradually goes up also forming hills. 2. How do the tracings change as the stimulus rate is increased?it is steeper and then it gradually becomes consistent. 3. From your graph, estimate the stimulus rate above which there appears to be no significant increase in force. 3 stimuli / sec. 4. What stimulus intensity produced smooth force at Force = 2 gms? 2.5V. 5....