Developmental Pathophysiology, Develop. Physiol., Dr. D. Penney
Self-Assessment - Module 23:
1. In Tetralogy of Fallot:
- desaturation of arterial blood occurs
- extent of cyanosis is primarily a function of the degree of pulmonary stenosis
- may allow equalization of right and left ventricle pressures
- right to left shunting of blood is the rule
- all are correct.
2. At birth:
- pulmonary vascular resistance falls shortly after the first breath, because of pulmonary arteriolar vasodilation
- the initial left atrial pressure rise occurs because the ductus arteriosus has closed.
- the foramen ovale closes because of umbilical cord clamping.
- right to left shunting of blood through the ductus arteriosus continues right up till the ductus closes.
- the adult circulation is functional within a few minutes after birth.
3. You do oximetry on a young patient with suspected congenital heart disease, with the following results:
|Site||Oxygen saturation (%)|
|Inferior vena cava||69|
The values are most consistent with a diagnosis of:
- atrial septal defect
- coarctation of the aorta
- tricuspid atresia (i.e. valve and opening absent)
- patent ductus arteriosus
- ventricular septal defect
4. Which of the following statements are incorrect regarding the oxygen dissociation curve of human hemoglobin?
- the affinity for oxygen is decreased by more acid conditions (i.e. lower pH).
- the curve is "S' shaped.
- blood returning to the right atrium and right ventricle has given up its oxygen to body tissues and is completely lacking in oxygen.
- hemoglobin is almost completely saturated with oxygen (93-98%) at 100 mm Hg partial pressure of oxygen.
- increasing body temperature lowers hemoglobin's affinity for oxygen.
5. Which of the following statements best characterizes the ductus venosus of the fetus?
- it receives most of its blood from the umbilical vein
- it sends its blood to the liver
- both of the above statements are correct
- it contains blood of a lower oxygen content than the blood in the umbilical arteries
- statements A and D are correct
6. Which one of the following statements is incorrect regarding the ductus arteriosus?
- it is a shunt from the pulmonary artery to the aorta in the fetus
- blood flow may take place from the aorta to the pulmonary artery after birth, prior its closing.
- it is a shunt directly from the right atrium to the left atrium
- right to left blood flow decreases with the first breath after birth due to falling pulmonary vascular resistance.
- the smooth muscle in its walls is sensitive to rising PO2
7. The foramen ovale
- closes anatomically within seconds to minutes after birth
- permits about twice a much blood to pass to the left atrium as that which flows into the right ventricle during fetal life
- closes functionally at birth because left atrial pressure rises above right atrial pressure
- is a shunt around the liver, allowing blood to flow directly from the umbilical vein to the right atrium
- is a round hole in the interventricular septum between the right and left hearts
8. A patient is diagnosed as having an opening in the interatrial septum uncomplicated by other cardiac abnormalities. Which of the following would best confirm this diagnosis?
- a systolic murmur
- an elevated oxygen concentration in the right atrium
- arterial cyanosis
- a decreased pressure in the right atrium
More Self-Assessment Questions