Sirkulasi Prenatal dan Postnatal

Summary

This video explains the differences between prenatal and postnatal circulation in humans. It covers the key fetal shortcuts: foramen ovale, ductus arteriosus, and ductus venosus, which direct blood flow bypassing the lungs and liver. During pregnancy, blood rich in oxygen and nutrients from the placenta travels through these shortcuts to nourish the fetus. After birth, these pathways close, and the baby’s circulation transitions to a system similar to that of adults, involving systemic and pulmonary circulation. The process is essential for understanding how the circulatory system adapts from prenatal to postnatal life.

Takeaways

• 😀 Prenatal circulation in the fetus includes three main shortcuts: foramen ovale, ductus arteriosus, and ductus venosus.
• 😀 Foramen ovale connects the right and left atria of the heart, allowing blood to flow from the right atrium directly to the left atrium.
• 😀 Ductus arteriosus connects the pulmonary trunk and the aorta, allowing blood to bypass the lungs and flow directly into the systemic circulation.
• 😀 Ductus venosus connects the umbilical vein and the inferior vena cava, enabling blood to bypass the liver and flow directly into the heart.
• 😀 Blood from the placenta, rich in oxygen and nutrients, flows through the umbilical vein into the fetal circulation.
• 😀 Two-thirds of blood from the right atrium flows through the foramen ovale to the left atrium, while the remaining one-third goes to the right ventricle.
• 😀 The majority of blood from the right ventricle passes through the ductus arteriosus into the aorta, bypassing the lungs.
• 😀 After birth, the fetal shortcuts (foramen ovale, ductus venosus, and ductus arteriosus) close and are replaced by permanent structures.
• 😀 The closure of the foramen ovale results in the formation of the fossa ovalis due to increased pressure in the left atrium after birth.
• 😀 The ductus venosus closes after birth due to the cessation of blood flow from the placenta following the cutting of the umbilical cord.
• 😀 The ductus arteriosus closes after birth as blood flow to the lungs increases, and it forms the ligamentum arteriosum.

Q & A

What are the three shortcuts in fetal circulation?

The three shortcuts in fetal circulation are the foramen ovale, ductus arteriosus, and ductus venosus.

What is the role of the foramen ovale in fetal circulation?

The foramen ovale connects the right atrium (atrium dextrum) to the left atrium (atrium sinistrum) in the fetus, allowing blood to flow directly from the right to the left atrium, bypassing the pulmonary circulation.

How does the ductus arteriosus function in fetal circulation?

The ductus arteriosus connects the pulmonary trunk (truncus pulmonalis) to the aorta, allowing blood to bypass the lungs, which are not yet in use for oxygen exchange.

What is the function of the ductus venosus in fetal circulation?

The ductus venosus connects the umbilical vein to the inferior vena cava, allowing blood from the placenta to bypass the liver and flow directly into the heart.

How does blood flow through the fetus starting from the placenta?

Blood from the placenta flows through the umbilical vein into the ductus venosus, then into the inferior vena cava, and from there, it flows into the right atrium. A large portion of the blood bypasses the right ventricle through the foramen ovale into the left atrium.

What happens to the blood from the right atrium after it passes through the foramen ovale?

After passing through the foramen ovale, blood flows into the left atrium, then into the left ventricle, and finally into the aorta to supply oxygen and nutrients to the rest of the body.

How does fetal circulation differ from postnatal circulation?

Fetal circulation includes shortcuts like the foramen ovale, ductus arteriosus, and ductus venosus to bypass the lungs and liver, while postnatal circulation involves the normal pathway where blood circulates through the lungs and liver for oxygenation and detoxification.

What changes occur in the circulatory system immediately after birth?

After birth, the foramen ovale, ductus venosus, and ductus arteriosus close as the lungs and liver begin to function, and the circulatory system transitions to normal postnatal circulation.

What causes the closure of the foramen ovale after birth?

The closure of the foramen ovale occurs because the increased pressure in the left atrium after birth causes the valve to close, forming the fossa ovalis.

What happens to the ductus arteriosus after birth?

After birth, the increased blood flow to the lungs causes the ductus arteriosus to close and form the ligamentum arteriosum, preventing blood from bypassing the lungs.