Fetal Development Questions Key

What might happen to a baby if:

1. Its foramen ovale remained open after birth? – this opening allows blood from the right atrium and left atrium to mix. After birth, the left atrium will pump blood into the right atrium (because the left side of the heart is stronger than the right side) and that blood will go to the lungs. Less blood will go to the body and more to the lungs.

2. Its ductus arteriosus remained open after birth? – this duct connects the pulmonary trunk and the aorta. Blood will flow from the aorta to the pulmonary trunk (because the aorta has a higher pressure in it). Less blood will go to the body and more to the lungs.

3. Its ductus venosus remained open after birth? – this vein connects the hepatic portal vein to the inferior vena cava, bypassing the liver. Blood from the GI tract will be delivered straight to the heart and the rest of the body, without having its nutrient levels controlled or its toxins removed. The liver will not remove urea from the blood, deactivate hormones like aldosterone, T3 and insulin, or remove bile pigments. The child will be jaundiced and may have other complications of liver failure.

4. It continued to synthesize only fetal hemoglobin after birth? – fetal hemoglobin has a high O2 affinity. It holds the O2 and does not release it to the tissues readily. The baby’s tissues would lack O2. Its kidneys might secrete erythropoietin, causing it to make too many RBCs. Its heart might be stimulated to beat too hard, causing heart failure. Its respiration might be stimulated as well.