What is the fetal circulation?

The fetal circulation system is distinctly different from adult circulation. This intricate system allows the fetus to receive oxygenated blood and nutrients from the placenta. It is comprised of the blood vessels in the placenta and the umbilical cord, which contains two umbilical arteries and one umbilical vein.

What is fetal circulation quizlet?

A vein that brings oxygenated blood back towards the fetal heart from the umbilical cord. …

What are the 3 shunts in fetal circulation?

Three shunts in the fetal circulation

  • Ductus arteriosus. � protects lungs against circulatory overload. � allows the right ventricle to strengthen. …
  • Ductus venosus. � fetal blood vessel connecting the umbilical vein to the IVC. …
  • Foramen ovale. � shunts highly oxygenated blood from right atrium to left atrium.

Why is the process of fetal circulation necessary quizlet?

To get oxygenated blood from the right side of the heart over to systemic circulation. Because it is already oxygenated and doesn’t need to go through pulmonary circuit to pick up oxygen.

How does fetal circulation allow blood to bypass the lungs quizlet?

Fetal circulation has two routes to bypass the pulmonary circuit: the foramen ovale, an opening in the interatrial septum, and thus ductus arteriosus, a shunt between the pulmonary trunk and the aorta.

Why are there 2 umbilical arteries?

Usually, an umbilical cord has two arteries, along with a single vein, making a total of three vessels. The vein carries oxygen and nutrients to your baby, and the arteries remove waste products.


What are the 4 shunts in fetal circulation?

Blood circulation after birth

The closure of the ductus arteriosus, ductus venosus, and foramen ovale completes the change of fetal circulation to newborn circulation.

Why do we have 2 umbilical arteries?

Here’s what exactly it means for you and baby throughout your pregnancy. What is a two-vessel umbilical cord? Most babies’ umbilical cords have three blood vessels: one vein, which brings nutrients from the placenta to baby, and two arteries that bring waste back to the placenta.

Why is the process of fetal circulation is necessary?

Through the blood vessels in the umbilical cord, the fetus receives all the necessary nutrition, oxygen, and life support from the mother through the placenta. Waste products and carbon dioxide from the fetus are sent back through the umbilical cord and placenta to the mother’s circulation to be eliminated.

Which of the following is a feature of fetal circulation?

The fetal circulation is characterized by high pulmonary vascular resistance, decreased pulmonary blood flow (only 10% OF right ventricular output), decreased systemic vascular resistance (presence of placenta), and right-to-left flow through the patent ductus arteriosus (PDA) and the foramen ovale.

Which of the following is the role of the umbilical vein in fetal circulation quizlet?

The umbilical vein carries oxygenated blood with maternal nutrients from the placenta to the fetus. The umbilical arteries carry deoxygenated blood with fetal waste from the fetus to the placenta. … This venous duct acts as a liver bypass and moves blood into the fetal systemic circulation.

What are the changes of fetal circulation at birth?

At birth, major changes take place. The umbilical cord is clamped and the baby no longer receives oxygen and nutrients from the mother. With the first breaths of air, the lungs start to expand, and the ductus arteriosus and the foramen ovale both close.

What is the function of the foramen ovale during fetal life?

Before birth, the foramen ovale allows blood flow to bypass the lungs (a fetus gets the oxygen it needs from the placenta, not the lungs). That way, the heart doesn’t work hard to pump blood where it isn’t needed. When newborns take their first breath, a new flow direction happens.

What is the function of the umbilical artery in the fetus?

The umbilical vein carries oxygenated, nutrient-rich blood from the placenta to the fetus, and the umbilical arteries carry deoxygenated, nutrient-depleted blood from the fetus to the placenta (Figure 2.2). Any impairment in blood flow within the cord can be a catastrophic event for the fetus.

How many veins are in the umbilical?

The umbilical cord is a tube that connects you to your baby during pregnancy. It has three blood vessels: one vein that carries food and oxygen from the placenta to your baby and two arteries that carry waste from your baby back to the placenta.

What are the main differences between fetal circulation and circulation in adults?

Fetal circulation is markedly different from circulation in adults. In the fetus, the main filtration site for plasma nutrients and wastes is the placenta, which is outside of the body cavity. In adults, the circulation occurs entirely inside the body.

How many umbilical vein are there?

Umbilical cord embryology

Coursing through the body stalk are two umbilical arteries, two umbilical veins and the allantois. Initially, the left and right umbilical arteries are caudal continuations of the primitive dorsal aortae, but after several revisions finally arise from the internal iliac arteries.

What are the 3 fetal shunts and what are their functions?

The fetal circulatory system bypasses the lungs and liver with three shunts. The foramen ovale allows the transfer of the blood from the right to the left atrium, and the ductus arteriosus permits the transfer of the blood from the pulmonary artery to the aorta.

What is the amniotic fluid?

Amniotic fluid is a clear, slightly yellowish liquid that surrounds the unborn baby (fetus) during pregnancy. It is contained in the amniotic sac. Polyhydramnios may occur when a fetus cannot swallow a normal amount of amniotic fluid due to a gastrointestinal, neurological, or other problem.

What are umbilical veins?

The umbilical vein is the conduit for blood returning from the placenta to the fetus until it involutes soon after birth. The umbilical vein arises from multiple tributaries within the placenta and enters the umbilical cord, along with the (usually) paired umbilical arteries.

Why is fetal circulation different?

The fetal circulation system is distinctly different from adult circulation. … Fetal circulation bypasses the lungs via a shunt known as the ductus arteriosus, the liver is also bypassed via the ductus venosus and blood can travel from the right atrium to the left atrium via the foramen ovale.

How many arteries and veins are in fetal circulation?

Once there is adequate fetal-placental circulation established, blood transports between fetus and placenta through the umbilical cord containing two umbilical arteries and one umbilical vein.

Which vein is present in umbilical cord?

Once there is adequate fetal-placental circulation established, blood transports between fetus and placenta through the umbilical cord containing two umbilical arteries and one umbilical vein.

What are the main events that occur in fetal circulation in utero and after delivery?

The umbilical cord is clamped and the baby no longer receives oxygen and nutrients from the mother. With the first breaths of air, the lungs start to expand and the ductus arteriosus and the foramen ovale both close. The baby’s circulation and blood flow through the heart now function like an adult’s.

Does the mother and fetal blood mix explain?

The mother’s blood does not normally mix with the baby’s blood during the pregnancy, unless there has been a procedure (such as amniocentesis or chorionic villus sampling) or vaginal bleeding. During delivery, however, there is a good chance that some of the baby’s blood cells will enter the mother’s bloodstream.

Why does blood bypass the lungs in fetal circulation?

The fetal circulatory system uses 3 shunts. These are small passages that direct blood that needs to be oxygenated. The purpose of these shunts is to bypass the lungs and liver. That’s because these organs will not work fully until after birth.

How does fetal circulation differ from circulation after birth quizlet?

How does fetal circulation differ from circulation after birth? The umbilical vein carries oxygenated blood, while deoxygenated blood is carried by the umbilical arteries. … The infant takes its first breath and the lungs expand to increase blood oxygen levels.

What is the function of the foramen ovale during fetal life quizlet?

The foramen ovale is a hole in the atrial septum during fetal life that alows the blood to skip the lungs and go straight through to the aorta.

What role does the ductus arteriosus play in fetal circulation quizlet?

In the developing fetus, the ductus arteriosus, is a blood vessel connecting the pulmonary artery to the aortic arch. It allows most of the blood from the right ventricle to bypass the fetus’s fluid-filled non-functioning lungs. Upon closure at birth, it becomes the ligamentum arteriosum.

How does the fetal circulation differ from the newborn?

There is actually no direct contact between the circulatory systems of the mother and fetus. The fetus does not use its own lungs until birth, so its circulatory system is different from that of a newborn baby. Before birth, the fetal heart does not have to pump blood to the lungs to pick up oxygen.

When a child is born what happens to its blood circulation?

Its circulatory system must reorient itself to send all the blood through the lungs to receive oxygen. The baby is cut off from the placenta, which was previously its only source of nourishment. The blood vessels that ran through the umbilical cord constrict and close.

Where does the umbilical vein enter the circulation of the fetus?

The oxygen rich blood then returns to the fetus via the third vessel in the umbilical cord (umbilical vein). The oxygen rich blood that enters the fetus passes through the fetal liver and enters the right side of the heart.

What are the 3 functions of the umbilical cord?

The umbilical cord has three functions for the developing fetus: it supplies oxygen, it delivers nutrients, and it helps to withdraw blood rich in carbon dioxide and depleted in nutrients. Blood from the umbilical cord can also be used to treat a variety of diseases, much like bone marrow.

Why is the blood of the mother separated from the blood of the fetus?

The placenta produces a number of hormones that are needed during pregnancy, such as lactogen, oestrogen and progesterone. It keeps the mother’s blood separate from the baby’s blood to protect the baby against infections.

Can a fetus survive without an umbilical cord?

In these early weeks, there’s no need to breathe. The umbilical cord is the main source of oxygen for the fetus. As long as the umbilical cord remains intact, there should be no risk of drowning in or outside the womb.

What is the umbilical cord made of?

At full term, an umbilical cord is about half a meter long, a length that allows the baby to move around safely. It is made up of two small arteries and one larger vein. The arteries carry blood from the fetus to the placenta, while the vein delivers blood from the placenta to the fetus.

Can a babies pull out the umbilical cord in the womb?

If the baby’s umbilical cord is short the baby’s movements may stretch and tear either the umbilical cord or the mother’s placenta (known as placental abruption). Ideally, an umbilical cord should be long enough for the baby to move without stretching the cord, but not so long as to easily get knotted or tangled.

What is fetal circulation in Wikipedia?

In animals that give live birth, the fetal circulation is the circulatory system of a fetus. The term usually encompasses the entire fetoplacental circulation, which includes the umbilical cord and the blood vessels within the placenta that carry fetal blood.