Exercício 2 - Atividade 4 (tétano)

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<p>Name: Jônatas Sousa dos Anjos</p><p>Exercise 2: Skeletal Muscle Physiology: Activity 4: Tetanus in Isolated Skeletal Muscle Lab Report</p><p>Pre-lab Quiz Results</p><p>You scored 100% by answering 3 out of 3 questions correctly.</p><p>1. Stimulus frequency refers to</p><p>You correctly answered: b. the rate that stimulating voltage pulses are applied to an isolated whole skeletal muscle.</p><p>2. Which of the following distinguishes a state of unfused tetanus from a state of complete (fused) tetanus?</p><p>You correctly answered: d. Muscle tension increases and decreases during a state of unfused tetanus.</p><p>3. When the stimulus frequency reaches a value beyond which no further increases in force are generated by the muscle,</p><p>the muscle has reached its</p><p>You correctly answered: a. maximal tetanic tension.</p><p>04/08/24 page 1</p><p>04/08/24 page 2</p><p>Experiment Results</p><p>Predict Question:</p><p>Predict Question: As the stimulus frequency increases further, what will happen to the muscle tension and twitch</p><p>appearance with each successive stimulus? Will there be a limit to this response?</p><p>Your answer : c. As the stimulus frequency increases, the muscle tension generated by each successive stimulus will</p><p>remain the same.</p><p>Stop & Think Questions:</p><p>What begins to happen at around 80 msec?</p><p>You correctly answered: c. unfused tetanus develops</p><p>How does the trace at 130 stimuli/sec compare with the trace at 50 stimuli/sec?</p><p>You correctly answered: b. Fused tetanus develops at this greater stimulus frequency.</p><p>How do the traces with 146–150 stimuli per second compare with the trace at 130 stimuli per second?</p><p>You correctly answered: d. Maximal tetanic tension develops with these very high stimulation frequencies.</p><p>Experiment Data:</p><p>Voltage Length Stimuli/sec Active Force Passive Force Total Force</p><p>8.5 75 50 5.12 0.0 5.12</p><p>8.5 75 130 5.88 0.0 5.88</p><p>8.5 75 140 5.91 0.0 5.91</p><p>8.5 75 142 5.92 0.0 5.92</p><p>8.5 75 144 5.94 0.0 5.94</p><p>8.5 75 146 5.95 0.0 5.95</p><p>8.5 75 148 5.95 0.0 5.95</p><p>8.5 75 150 5.95 0.0 5.95</p><p>04/08/24 page 3</p><p>04/08/24 page 4</p><p>04/08/24 page 5</p><p>04/08/24 page 6</p><p>Post-lab Quiz Results</p><p>You scored 100% by answering 3 out of 3 questions correctly.</p><p>1. The term tetanus refers to</p><p>You correctly answered: b. sustained muscle tension due to very frequent stimuli.</p><p>2. Which of the following distinguishes a state of unfused tetanus from a state of complete (fused) tetanus?</p><p>You correctly answered: d. Muscle tension increases and decreases between different values for an unfused tetanus.</p><p>3. When the stimulus frequency reaches a value beyond which no further increases in force are generated by the muscle,</p><p>the muscle has reached its</p><p>You correctly answered: a. maximal tetanic tension.</p><p>04/08/24 page 7</p><p>Review Sheet Results</p><p>1. Describe how increasing the stimulus frequency affected the force developed by the isolated whole skeletal muscle in</p><p>this activity. How well did the results compare with your prediction?</p><p>Your answer:</p><p>Conforme a frequencia do estímulo aumenta, a força ou tensão exercida pelo músculo também aumenta, de modo que</p><p>existe um limite para o máximo de força que se pode alcançar, que no caso do experimento foi a partir de 146 estímulos</p><p>por segundo.</p><p>2. Indicate what type of force was developed by the isolated skeletal muscle in this activity at the following stimulus</p><p>frequencies: at 50 stimuli/sec, at 140 stimuli/sec, and above 146 stimuli/sec.</p><p>Your answer:</p><p>50 estímulos por segundo: Tensão de tétano incompleto (unfused tetanus).</p><p>140 estímulos por segundo: Tensão de tétano completo (fused tetanus).</p><p>Mais que 146 estímulos por segundo: Tensão tetânica máxima.</p><p>3. Beyond what stimulus frequency is there no further increase in the peak force? What is the muscle tension called at this</p><p>frequency?</p><p>Your answer:</p><p>Não há mais aumento de força/tensão muscular a partir de 146 estímulos por segundo, sendo esta força máxima</p><p>denominada tensão tetânica máxima.</p>