Exercise 6: Cardiovascular Physiology: Activity 5: Examining the Effects of Various Ions on Heart Rate Lab Report
Pre-lab Quiz Results
You scored 100% by answering 4 out of 4 questions correctly.
1. Which organelle in the cardiac muscle cell stores calcium?
You correctly answered: b. sarcoplasmic reticulum
2. Verapamil is a calcium-channel blocker. Its effects could be described as
You correctly answered: d. negative chronotropic and negative inotropic.
3. When the cardiac muscle cell is at rest, where is most of the potassium found?
You correctly answered: c. in the cytosol
4. Resting cardiac muscle cells are most permeable to
You correctly answered: b. potassium.
Post-lab Quiz Results
You scored 100% by answering 4 out of 4 questions correctly.
1. The addition of most of the ions resulted in
You correctly answered: c. an erratic heart rate.
2. The effect of potassium on the heart is
You correctly answered: b. negative chronotropic, negative inotropic.
3. The ion that had the most pronounced effect on heart rate was
You correctly answered: c. potassium.
4. Ectopic pacemakers can be caused by excessive leakage of potassium into cardiac cells, resulting in pacemakers
appearing in abnormal locations in the heart muscle. This hyperkalemia (excess potassium) decreases the resting potential
of the cardiac muscle cell. What effect do you think this would have on the force of contraction?
You correctly answered: d. decrease, negative inotropic
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