1. Half of the people have a smaller than average sized heart and half have a larger than average sized heart. In which group would you expect the heart rate to be higher? Explain your answer.

2. In general, females have a higher heart rate than males. What explanation can you give for this difference?

3. What important molecule is carried by blood entering the left heart pump and is not in the blood entering the right heart pump?

4. If the fetal hole between the right and left atria does not close, what happens to the blood in these two chambers?

5. Which ventricle operates under the most pressure (does the most work)?

6. What would happen to the pressure in the two ventricles if there was a hole between them?

7. What would the heart do to compensate for the pressure problem created by a ventricle hole? Hint: People with this abnormal hole must have it repaired while they are young or they won’t live long.

8. A patient is told that she has a narrowing of the right coronary artery. Which chambers of her heart are going to be affected the most by this disorder? Which chamber on the right side has to do the most work and could be the most serious health concern?

9. A group of patients were told that they had plugged arteries in their hearts. In addition, they had all suffered a similar size of heart attack. All of these patients survived. Some of them had parts of their injured hearts return almost to normal after several months. The other patients had no such luck. Explain these differences in terms of coronary circulation.

10. A heart attack on which side of the heart would probably cause the most serious immediate risk to the person?

11. What would happen to blood flow if one of the valve “cords” broke? Be specific.

12. What would happen to blood flow if one of the valves was scarred by disease, narrowing the opening?

13. If you had a moderate heart valve problem, what would the heart have to do to compensate?

14. On which side of the heart would a moderate heart valve problem have more consequence to your health? Explain your answer.

15. Arteriosclerosis hardens the artery wall with scar tissue. If arteries have been partially injured by arteriosclerosis and the arterial wall is less flexible than normal, then would the pulse be stronger or weaker than normal? Why?