PEX Exercise 2 Activity 5

Satisfactory Essays
Name: Lindsey Weber
Exercise 2: Skeletal Muscle Physiology: Activity 5: Fatigue in Isolated Skeletal Muscle Lab Report
Pre-lab Quiz Results
You scored 100% by answering 4 out of 4 questions correctly.
1. When skeletal muscle twitches fuse so that the peaks and valleys of each twitch become indistinguishable from each other, the muscle is in a state known as
You correctly answered: d. complete (fused) tetanus.
2. When the stimulus frequency reaches a value beyond which no further increase of skeletal muscle force can occur, the muscle has reached its
You correctly answered: c. maximal tetanic tension.
3. A decline in a muscle's ability to maintain a constant level of force, or tension, after prolonged, repetitive stimulation is called You correctly answered: c. fatigue.
4. Which of the following is not thought to be a contributing factor to the development of fatigue?
You correctly answered: a. buildup of Ca2+ in the muscle fibers


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Experiment Results
Predict Question:
Predict Question: If the stimulator is briefly turned off for defined periods of time, what will happen to the length of time that the muscle is able to sustain maximal developed tension when the stimulator is turned on again?
Your answer : b. The length of the rest period will proportionately increase the length of time for sustained muscle tension.
Stop & Think Questions:
Why does the stimulated muscle force begin to decrease over time despite the maintained stimuli? (Note that a decrease in maximal force indicates muscle fatigue is developing.)
You correctly answered: d. More than one of these answers could be correct.
Why did the length of the intervening rest period affect the length of time the skeletal muscle can maintain maximum tension once the stimulator is turned on again?
You correctly answered: c. Intracellular concentrations of ADP and Pi declined during the rest period.
Experiment Data:


Rest Period (sec)

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