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…show more content…
Activity 7: Investigating Muscle Fatigue
1. Why does the force begin to decrease with time? Note that a decrease in force indicates muscle fatigue.
Because there is not enough ATP being produced to allow the muscle to contract that many times and for the length of time.
2. The muscle will produce force for a longer period if the stimulator is briefly turned off than if the stimulations were allowed to continue without interruption. Explain why. Because for the brief time that the stimulation is off the muscle can produce more ATP to supply the contractions with.
3. Describe the difference between the current tracing and the myogram generated in step 6.
The current tracing does not dip as much but gradually decreases as the muscle fatigues.
Activity 8: Investigating Isometric Contraction
1. What happens to the passive force as the muscle length is increased from 50mm to 100mm?
The passive force increases.
2. What happens to the active force as the muscle length is increased from 50mm to 100mm?
The active force increases until 74-76 then starts to decrease again.
3. What happens to the total force as the muscle length is increased from 50mm to 100 mm?
It does the same thing as the active force does except for in increases at the end again.
4. Explain the dip in the total