Welcome everyone! Today we will discuss about fetal circulation simply and easily to understand for nusing and medical students
Fetal Circulation
The embryo develops separate circulation from 16 to week after fertilization The fetal heart starts beating from the 21st day of fertilization
A single umbilical vein carries 80% oxygenated blood from the placenta towards
the fetus.
While it is moving toward the heart of the fetus one branch will give blood to
the fetal liver.
Then the umbilical vein enters into the inferior vena cava through ductus venosus and it empty into the right atrium.
From the right atrium majority of the blood will move toward the left atrium via the foramen ovale and the remaining blood will move towards the right ventricle through the tricuspid valve.
The blood in the left atrium will move toward the left ventricle via bicuspid valve (mitral valve).
During systole the blood in the left ventricle moves towards the aorta- and it supplies the body parts of the fetus.
The blood in the right ventricle moves towards the pulmonary artery. But in the fetal state pulmonary system pressure is higher than the systemic pressure so blood will move from the pulmonary artery to the aorta via ductus arteriosus.
Two umbilical arteries carry deoxygenated blood from various parts of the fetal body towards the placenta
After the birth of the newborn, all these connections will closed
- Ductus venosus becomes ligamentum venosum
- Ductus arteriosus become ligamentum arteriosum
- Foramen ovale become fossa ovalis
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