Chapter 24: Congenital Cardiac Defects Test Bank
MULTIPLE CHOICE 1. Which of the following vessels return blood to the right ventricle?
I. Pulmonary vein II. Inferior vena cava III. Superior vena cavaIV. Coronary sinus a. b. II and III only c. I, II, and III only d. II, III, and IV only
I and IV only
ANS: D
To understand the normal anatomy of the heart, one can trace the path of blood as it travels through the heart. This begins with deoxygenated venous blood that enters the right atrium (RA) from one of three sources. Venous blood from organs superior to the heart drains to the RA by way of the superior vena cava (SVC). Venous blood from organs inferior to the heart enters the RA via the inferior vena cava (IVC). Finally, venous blood from the heart itself drains into the RA by way of the coronary sinus. REF: p. 471 2. At birth, what factor causes dilation of the pulmonary vascular bed and a decrease in the
pulmonary vascular resistance? a. Increased arterial partial pressure of oxygen (PaO2) b. Decreased arterial partial pressure of carbon dioxide (PaCO2) c. Lung inflation d. Circulating indomethacin ANS: A
With inflation of the lungs and the beginning of their participation in gas exchange, PaO2 increases and PaCO2 decreases, both of which contribute to dilation of the pulmonary vasculature and a resultant reduction in pulmonary vascular resistance (PVR). This leads to reduced right ventricular pressures and increased pulmonary blood flow. REF: p. 472 3. What factor is responsible for closure of the foramen ovale? a. Increased PaO2 b. Increased pressure on the left side of the heart c. Blood flowing through the lungs d. High pulmonary vascular resistance ANS: B
