PhysioEx Lab Report Exercise 2: Skeletal Muscle Physiology Activity 4: Tetanus in Isolated Skeletal Muscle Name: Date: 15 September 2020 Pre-lab Quiz Results You scored 100% by answering 3 out of 3 questions correctly. 1 Stimulus frequency refers to You correctly answered: 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: 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: maximal tetanic tension. Experiment Results Predict Question 1 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: 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 1 What begins to happen at around 80 msec? You correctly answered: unfused tetanus develops. How does the trace at 130 stimuli/sec compare with the trace at 50 stimuli/sec? You correctly answered: Fused tetanus develops at this greater stimulus frequency. 3 How do the traces with 146-150 stimuli per second compare with the trace at 130 stimuli per second? You correctly answered: Maximal tetanic tension develops with these very high stimulation frequencies. Experiment Data Voltage (v) Length (mm) Stimuli/sec Act. Force Pass. Force Total Force 8.5 75 50 5.12 0 5.12 8.5 75 130 5.88 0 5.88 8.5 75 140 5.91 0 5.91 8.5 75 150 5.95 0 5.95 Stimuli/sec = 50 at 8.5 V Stimuli/sec = 130 at 8.5 V Stimuli/sec = 140 at 8.5 V Stimuli/sec = 150 at 8.5 V Post-lab Quiz Results You scored 100% by answering 3 out of 3 questions correctly. 1 The term tetanus refers to You correctly answered: 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: 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: maximal tetanic tension.