Feta Circulation Flashcards
What are the names of the 3 shunts that allow fetal blood to bypass the lungs?
Ductus venosus:
This shunt connects the umbilical vein to the inferior vena cava and allows blood to bypass the liver.
Foramen ovale:
This shunt connects the right atrium with the left atrium and allows blood to bypass the right ventricle and pulmonary circulation.
Ductus arteriosus.
What does the ductus venous shunt connect?
The umbilical vein to the inferior vena cava
What does the ductus venous all blood to bypass?
The liver
What done the foramen ovale connect?
The right atrium with the left atrium
Ductus arteriosus.
What does the foramen ovale allow blood to bypass?
The right ventricle and pulmonary circulation.
What does the ductus arteriosus connect?
The pulmonary artery with the aorta
What does the ductus arteriosus allow blood to bypass?
The pulmonary circulation.
What happens when the baby takes its first few breaths?
The first breaths the baby takes expands the alveoli, decreasing the pulmonary vascular resistance
What does a decrease in pulmonary vascular resistance cause?
A fall in pressure in the right atrium.
What does the left atrial pressure being greater than the right atrial pressure cause?
This squashes the atrial septum to cause functional closure of the foramen ovale
What are required to keep the ductus arteriosus open?
Prostaglandins
What does increased blood oxygen cause?
A drop in circulating prostaglandins.
What does a drop in circulating prostaglandins cause?
The closure of the ductus arteriosus
What does the closed ductus arteriosus become?
The ligamentum arteriosum
When does the ductus venous stop functioning?
Immediately after birth
