Foetal Circulation And Congenital Heart Malformations

Question 1

[11-minute video]: Fetal circulation

Answer 1

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Question 2

What are common symptoms of Tetralogy of Fallot?

Answer 2

Common symptoms include cyanosis (bluish skin), shortness of breath, poor weight gain, and tet spells (sudden episodes of deep blue skin, nails, and lips after crying or feeding).
[Diagram 1] [Diagram 2]

Question 3

What is the primary source of oxygen and nutrients for the fetus?

Answer 3

The placenta, which provides oxygen and nutrients via the umbilical cord.

Question 4

What is the function of the umbilical vein?

Answer 4

The umbilical vein carries oxygenated blood from the placenta to the fetus.

Question 5

How many vessels are in the umbilical cord, and what are they?

Answer 5

The umbilical cord contains three vessels: one umbilical vein and two umbilical arteries.

Question 6

What is the role of the ductus venosus?

Answer 6

The ductus venosus allows blood to bypass the liver and flow directly into the inferior vena cava.

Question 7

What is the foramen ovale?

Answer 7

The foramen ovale is an opening between the right and left atria of the fetal heart, allowing blood to bypass the lungs.

Question 8

What is the ductus arteriosus?

Answer 8

The ductus arteriosus is a vessel that connects the pulmonary artery to the aorta, bypassing the lungs.

Question 9

Why do fetal lungs not function in gas exchange?

Answer 9

The fetus receives oxygenated blood from the placenta, so the lungs are not used for gas exchange before birth.

Question 10

What happens to the blood that enters the right atrium from the inferior vena cava?

Answer 10

It can flow through the foramen ovale into the left atrium or into the right ventricle and then through the ductus arteriosus to the aorta.

Question 11

What is the function of the umbilical arteries?

Answer 11

The umbilical arteries carry deoxygenated blood and waste products from the fetus to the placenta.

Question 12

What changes occur in fetal circulation after birth?

Answer 12

The foramen ovale closes, the ductus arteriosus constricts, and the umbilical vessels are no longer needed.

Question 13

How does blood bypass the fetal liver?

Answer 13

Blood bypasses the liver through the ductus venosus, which connects the umbilical vein to the inferior vena cava.

Question 14

What is the significance of the high resistance in fetal pulmonary circulation?

Answer 14

High resistance in the fetal lungs directs blood flow through the ductus arteriosus and foramen ovale, bypassing the non-functional lungs.

Question 15

What is Tetralogy of Fallot?

Answer 15

Tetralogy of Fallot is a congenital heart defect that involves four anatomical abnormalities: Ventricular Septal Defect (VSD), Pulmonary Stenosis, Overriding Aorta, and Right Ventricular Hypertrophy.
[Diagram 1] [Diagram 2]

Question 16

What is Right Ventricular Hypertrophy?

Answer 16

Right Ventricular Hypertrophy is the thickening of the muscular walls of the right ventricle, which occurs because the heart has to work harder to pump blood through the narrowed pulmonary valve.
[Diagram 1] [Diagram 2]

Question 17

What is a Ventricular Septal Defect (VSD)

Answer 17

A Ventricular Septal Defect (VSD) is a hole between the right and left ventricles of the heart.
[Diagram 1] [Diagram 2]

Question 18

What is Pulmonary Stenosis?

Answer 18

Pulmonary Stenosis is the narrowing of the pulmonary valve and the passage from the right ventricle to the pulmonary artery.
[Diagram 1] [Diagram 2]

Question 19

What is an Overriding Aorta?

Answer 19

An Overriding Aorta is when the aorta is positioned directly over the VSD, allowing oxygen-poor blood to flow into the aorta and out to the body.
[Diagram 1] [Diagram 2]