How does the fetal circulatory system work?

During pregnancy,the unborn baby (fetus) depends on its mother for nourishment and also oxygen. Due to the fact that the fetus doesn’t breathe air, their blood circulatesdifferently 보다 it walk after birth:

The placenta is the body organ that develops and implants in the mother"s womb (uterus) during pregnancy. The unborn infant is linked to the placenta through the umbilical cord.

All the vital nutrition, oxygen, and also life support from the mother’s blood goes through the placenta and to the baby through blood ship in the umbilical cord.

Waste products and also carbon dioxide native the baby space sent ago through the umbilical cordblood vesselsand placenta come the mother"s circulation to be eliminated.




You are watching: The organ that exchanges molecules between fetal and maternal blood is the

*

While quiet in the uterus, the baby"s lungs aren"t being used. The baby’s liver isn"t completely developed. Turn blood bypasses the lungs and also liver by flow in various pathways and through one-of-a-kind openings referred to as shunts.

Blood flow in the unborn baby follows this pathway:

Oxygen and nutrients indigenous the mother"s blood space transferred throughout the placenta come the fetus through the umbilical cord.

This enriched blood flows v the umbilical vein towards the baby’s liver. There it moves v a shunt dubbed the ductus venosus.

This allows some the the blood to walk to the liver. But most of this extremely oxygenated blood flows to a huge vessel referred to as the inferior vena cava and then right into the best atrium the the heart.

Here is what happens within the fetal heart:

When oxygenated blood from the mother enters the ideal side of the heart, the flows right into the top chamber (the ideal atrium). Most of the blood flows throughout to the left atrium through a shunt called the foramen ovale.

From the left atrium, blood moves down right into the reduced chamber the the heart (the left ventricle). It"s then pumped into the first part of the huge artery coming from the heart (the ascending aorta).

From the aorta, the oxygen-rich blood is sent tothe brain and to the heart muscle itself.Blood is likewise sent come the lower body.

Blood returning to the love from the fetal body has carbon dioxide and waste commodities as the enters the best atrium. It operation down into the ideal ventricle, wherein it generally would be sent out to the lung to it is in oxygenated. Instead, it bypasses the lungs and also flows through the ductus arteriosus into the to decrease aorta, which connects to the umbilical arteries. Indigenous there, blood flows ago into the placenta. There the carbon dioxide and also waste products are released into the mother"s circulatory system. Oxygen and nutrients indigenous the mother"s blood room transferred across the placenta. Then the cycle starts again.

At birth, significant changes take place. The umbilical cord is clamped and the baby no much longer receives oxygen and nutrients native the mother. With the very first breaths that air, the lungs start to expand and also the ductus arteriosusand the foramen ovale both close.

See more: Br A Multiple Choice Test Has 10 Questions Each Of Which Has 4 Possible Answers

The baby"s circulation and also blood flow through the love now function like an adult"s.