PhysioEx Exercise 6 Activity 5.pdf - PhysioEx Exercise 6 Activity 5 PhysioEx Lab Report Exercise 6 Cardiovascular Physiology Activity 5 Examining the

PhysioEx Exercise 6 Activity 5.pdf - PhysioEx Exercise 6...

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Unformatted text preview: 4/15/2020 PhysioEx Exercise 6 Activity 5 PhysioEx Lab Report Exercise 6: Cardiovascular Physiology Activity 5: Examining the Effects of Various Ions on Heart Rate Name: Courtney Paulsen Date: 15 April 2020 Session ID: session-d474c3c2-f392-83cf-7256-4f2f1af6bf74 Pre-lab Quiz Results You scored 75% by answering 3 out of 4 questions correctly. 1 Which organelle in the cardiac muscle cell stores calcium? You correctly answered: sarcoplasmic reticulum. 2 Verapamil is a calcium-channel blocker. Its effects could be described as You correctly answered: negative chronotropic and negative inotropic. 3 When the cardiac muscle cell is at rest, where is most of the potassium found? Your answer: in the sarcoplasmic reticulum. Correct answer: in the cytosol. 4 Resting cardiac muscle cells are most permeable to You correctly answered: potassium. Experiment Results Predict Questions 1 Predict Question 1: Because calcium-channel blockers are negative chronotropic and negative inotropic, what effect do you think increasing the concentration of calcium will have on heart rate? Your answer: positive chronotropic, positive inotropic. 2 Predict Question 2: Excess potassium outside of the cardiac cell decreases the resting potential of the plasma membrane, thus decreasing the force of contraction. What effect (if any) do you think it will initially have on heart rate? Your answer: increase heart rate. Stop & Think Question 1/4 4/15/2020 PhysioEx Exercise 6 Activity 5 1 Where in the cardiac muscle cell is most of the sodium normally found? You correctly answered: outside of the cell. Experiment Data Solution Heart Rate (beats/min) ---- 59 Calcium 69 Sodium ~34 Potassium ~28 2/4 4/15/2020 PhysioEx Exercise 6 Activity 5 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: an erratic, decreased heart rate. 2 The effect of potassium on the heart is You correctly answered: negative chronotropic, negative inotropic. 3 The ion that had the most pronounced effect on heart rate was You correctly answered: 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: decrease, negative inotropic. Review Sheet Results 1 Describe the effect that increasing the calcium ions had on the heart in this activity. How well did the results compare with your prediction? Your answer: Increasing calcium ions caused an increased heart rate. My prediction was correct since the modifiers that increase are positive inotropic and chronotropic. 2 Describe the effect that increasing the potassium ions initially had on the heart in this activity. Relate this to the resting membrane potential of the cardiac muscle cell. How well 3/4 4/15/2020 PhysioEx Exercise 6 Activity 5 did the results compare with your prediction? Your answer: The effect of increasing the potassium ions caused the heart rate to decrease and with the increase of potassium, this lowers the resting membrane potential. I predicted that it will increase and I was wrong. 3 Describe how calcium channel blockers are used to treat patients and why? Your answer: The use of calcium channel blockers is used to block calcium movement through the channels of cardiac action potentials. They are used to treat patients with high blood pressure and abnormal heart rates. 4/4 ...
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