Contraction of Cardiac Muscle Worksheet
Autor: Maryam • January 29, 2018 • 620 Words (3 Pages) • 944 Views
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Experiment 4: Effect of a Low Oxygen Environment
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Figure 5. The effect of a low oxygen environment on the force of contraction in toad cardiac muscle.
(4A) How did the active tension at the end of the time in the ‘de-oxygenated’ solution compare with that produced by the muscle strip in the normal oxygen-containing solution? Present this in a quantitative way (e.g. % change from contractile response with normal oxygenated solution). You must show your calculations.
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(4B) Briefly describe why oxygen is so important for the contraction of cardiac muscle.
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(4C) Explain the effect of the ‘de-oxygenated’ solution on the active tension developed by the cardiac muscle.
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Experiment 5: Effect of Drug A
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Figure 6. The effects of drug A and drug B on the force of contraction in toad cardiac muscle.
(5A) Quantify the effect of Drug A on the active tension developed by the cardiac muscle. For example, what was the percentage increase or decrease in active tension produced by Drug A in your preparation (i.e. compare the size of the active tension before and after the addition of Drug A)? You must show your calculations.
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(5B) Is Drug A the beta receptor agonist or the calcium channel blocker?
Explain your choice in the context of the effects of Drug A on the force of contraction. How does it cause this effect? Explain using the cardiac intracellular pathways involved to produce this effect.
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Experiment 6: Effect of Drug B
(6A) Is Drug B the beta receptor agonist or the calcium channel blocker?
Explain your choice in the context of the effects of Drug B on the force of contraction. How does it cause this effect? Explain using the cardiac intracellular pathways involved to produce this effect.
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Conclusion
Provide a brief conclusion of what you consider these experiments showed about the control of the strength of cardiac muscle contraction, and how this relates to the function of the heart in the intact animal.
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