Review of Section 2 : Self-test
Find the answers by scrolling to the bottom of the page.
1. Which organ is formed first in the human embryo?
2. The fetal heart is a miniature version of the adult heart by what age in development?
3. What changes occur shortly after birth in the human heart?
4. What disease processes interfere with heart development?
5. What condition does Dextrocardia and Dextroversion describe?
6. The coronaries supply blood to the muscle tissue and what other system?
7. What percentage of blood flows into resting myocardium ?
8. Coronary disease mainly affects the function of which chamber?
9. Where do the right and left coronary arteries originate?
10. Name the branches of the LEFT coronary artery.
11. Name the branches of the RIGHT coronary artery.
12. Into what vessel does waste-laden blood from the myocardium drain after the nutrient exchange has occurred?
13. Arterial blood flow is dependent on what two factors?
14. What happens to normal coronaries when an increased workload is put on the heart?
15. What happens to anastomoses in the myocardium when the blood supply becomes compromised?
ANSWERS
1. The heart and blood vessels are formed before any other organ.
2. By the eight week of fetal development, the heart possesses four chambers.
3. The foramen ovale should be closed completely. The ductus arteriosus shrinks, closing in about a week.
4. Rubella and rubeola (measles) viruses may interfere with heart development.
5. Dextrocardia and Dextroversion describe a congenital condition whereby the heart is positioned in the right half of the torso.
6. The coronary arteries supply blood, oxygen, and nutrients to the heart muscle and the conduction system.
7. Resting myocardium receives less than 5% of the cardiac output.
8. Because the muscle mass of the left ventricle exceeds that of the right ventricle, the coronary arteries need to supply more blood and oxygen to the left ventricle than to the right.
9. They originate at the base of the aorta, commonly known as the aortic root.
10. The Left Anterior Descending and the Left Circumflex Arteries.
11. The Marginal Branch and the Posterior Descending Artery.
12. The Coronary Sinus.
13. Arterial flow in the coronary arteries is dependent on the blood pressure and vascular resistance.
14. In the healthy heart, the coronary arteries can meet increased demand by dilating and increasing coronary blood flow, delivering more oxygen.
15. When a large area of the heart is deprived of blood, these anastomoses enlarge and then provide a collateral blood supply to the affected muscle.
