activity 4 PEX-02-04.pdf

Name: Kelompok 4 Exercise 2: Skeletal Muscle Physiology: Activity 4: Tetanus in Isolated Skeletal Muscle Lab Report Pre-lab Quiz Results You scored 100% by answering 3 out of 3 questions correctly. 1. Stimulus frequency refers to You correctly answered: b. the rate that stimulating voltage pulses are applied to an isolated whole skeletal muscle. 2. Which of the following distinguishes a state of unfused tetanus from a state of complete (fused) tetanus? You correctly answered: d. Muscle tension increases and decreases during a state of unfused tetanus. 3. When the stimulus frequency reaches a value beyond which no further increases in force are generated by the muscle, the muscle has reached its You correctly answered: a. maximal tetanic tension.

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Experiment Results Predict Question: Predict Question: As the stimulus frequency increases further, what will happen to the muscle tension and twitch appearance with each successive stimulus? Will there be a limit to this response? Your answer : b. As the stimulus frequency increases, the muscle tension generated by each successive stimulus will increase. There will be a limit to this increase. Stop & Think Questions: What begins to happen at around 80 msec? You correctly answered: c. unfused tetanus develops How does the trace at 130 stimuli/sec compare with the trace at 50 stimuli/sec? You correctly answered: b. Fused tetanus develops at this greater stimulus frequency. How do the traces with 146–150 stimuli per second compare with the trace at 130 stimuli per second? You correctly answered: d. Maximal tetanic tension develops with these very high stimulation frequencies. Experiment Data: Voltage 8.5 8.5 8.5 8.5 8.5 8.5 8.5 8.5

Length 75 75 75 75 75 75 75 75

Stimuli/sec 50 130 140 142 144 146 148 150

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Active Force 5.12 5.88 5.91 5.92 5.94 5.95 5.95 5.95

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Passive Force 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Total Force 5.12 5.88 5.91 5.92 5.94 5.95 5.95 5.95

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Post-lab Quiz Results You scored 100% by answering 3 out of 3 questions correctly. 1. The term tetanus refers to You correctly answered: b. sustained muscle tension due to very frequent stimuli. 2. Which of the following distinguishes a state of unfused tetanus from a state of complete (fused) tetanus? You correctly answered: d. Muscle tension increases and decreases between different values for an unfused tetanus. 3. When the stimulus frequency reaches a value beyond which no further increases in force are generated by the muscle, the muscle has reached its You correctly answered: a. maximal tetanic tension.

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Review Sheet Results 1. Describe how increasing the stimulus frequency affected the force developed by the isolated whole skeletal muscle in this activity. How well did the results compare with your prediction? Your answer: Prediksi sesuai dengan hasil eksperimen. Semakin besar frekuensi, semakin besar kekuatan kontraksi otot karena terjadi wave summation. Namun, terdapat nilai maksimum kontraksi (limit). 2. Indicate what type of force was developed by the isolated skeletal muscle in this activity at the following stimulus frequencies: at 50 stimuli/sec, at 140 stimuli/sec, and above 146 stimuli/sec. Your answer: Pada frekuensi 50 stimulus/detik dicapai unfused tetanus. Pada frekuensi 140 stimulus/detik dicapai fused tetanus. Pada frekuensi di atas 146 stimulus/detik otot mengalami fused tetanus dan telah mencapai maximum tetanic tension, sehingga active force yang dicapai tidak melebihi active force pada stimulus 146 stimulus/detik. 3. Beyond what stimulus frequency is there no further increase in the peak force? What is the muscle tension called at this frequency? Your answer: Di atas 146 stimulus/detik. Kekuatan otot ini disebut maximum tetanic tension.

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