Fetal Circulation and Transition To Extra-Uterine Life

Fetal Circulation and Transition To Extra-Uterine Life

Home Delivery - Fetal Circulation and Transition To Extra-Uterine Life Good morning. Yesterday, I learned about Home Delivery - Fetal Circulation and Transition To Extra-Uterine Life. Which could be very helpful if you ask me so you.

The amelioration of a human baby from a singular cell (one ovum unites with one sperm to form the zygote, the name given to fertilized ovum) and the subsequent transition from intra-uterine to extra uterine life is one of the many wonders of creation. It is to be remembered that the fetus cannot get atmospheric oxygen but is nourished by oxygen from the mom straight through the placenta. In order to achieve this, the fetus has a mechanism which would be extremely abnormal in extra uterine life. To understand this, first we need to understand the general circulation in adults. What I said. It isn't the actual final outcome that the real about Home Delivery. You see this article for information on a person wish to know is Home Delivery. Home Delivery The heart is a four chambered organ. The two upper chambers are called atria-left and right. The two lower ones are called ventricles -left and right. The 2 atria are completely separated by a structure called inter-atrial septum. Similarly the ventricles are separated by the inter-ventricular septum. Thus blood in the left side of the heart is completely separated from the blood in the right side. The right atrium receives blood from all the organ of the body straight through two main blood vessels-the classic vena cava and the inferior vena cava and then pumps that blood into the right ventricle. This blood is depleted of oxygen. The right ventricle pumps this blood into the lungs straight through a blood vessel called pulmonary artery, which divides into two one each for a lung. The main artery goes on dividing and subdividing till it reaches the sac like structures in the lungs called alveoli. The total exterior area of alveoli is roughly equal to the size of a tennis court. In the alveoli gas exchange takes place-carbon-dioxide is thrown out and oxygen is taken up by the blood. The wee blood vessels carry oxygenated blood into progressively larger blood vessels and ultimately this blood comes to the left atrium straight through four pulmonary veins. From the left atrium oxygenated blood enters the left ventricle straight through the left atrio-ventricular valve. The left ventricle then pumps blood into a big blood vessel called aorta. This gives off branches and supplies oxygenated blood to all the cells of the body-the whole process is no less involved than the water furnish and drainage principles of a town! Blood from the cells is again returned to the right atrium thus completing the cycle. The cycle goes on and on till the end of life. This can never work in a fetus because there is no direct access to atmospheric oxygen. Nature has devised a splendid mechanism to furnish oxygen to the fetus. The umbilical cord which forms the link in the middle of the mom and the fetus and is cut after birth, contains a blood vessel called umbilical vein. This vein carries oxygenated blood from the placenta into fetus. This divides into two inside the body of the fetus one field goes to the liver and the other called ductus venosus joins inferior vena cava, which carries deoxygenated blood to the right atrium. From this point the fetal circulation is different. As this oxygenated blood has to be supplied to all the fetal cells it has to go to the left side of the heart. There is no point in pumping it to lungs, which cannot carry out gas exchange. The inter-atrial septum in the fetus consists of two overlapping layers. They overlap in such a way that blood from the right atrium can enter the left atrium but the reverse cannot take place (valve like mechanism). The pressure in the right side heart in the fetus is higher than the left-exactly opposite to that after birth. Hence most of this blood goes into the left atrium, then to the left ventricle and pumped into aorta. The right atrium also receives deoxygenated blood from the upper parts of the body straight through the classic vena cava. This blood mixes with blood from the inferior vena cava (which carries blood with higher oxygen concentration) enters the right ventricle and then pumped into the pulmonary artery. In the fetus the pulmonary artery is connected to the aorta by a blood vessel called ductus arteriosus. Because there is no point in pumping blood into the lungs most of the blood in the pulmonary artery in shunted across the ductus arteriosus into the aorta. This blood contains less oxygen than that pumped by the left ventricle and supplies the lower parts of the body. The umbilical cord also contains two umbilical arteries. These arteries contain deoxygenated blood from the fetus into the placenta completing the cycle. Soon after birth the umbilical cord is clamped and cut. This increases resistance to systemic blood flow and raises the pressure in the left side of the heart. At the same time pulmonary pressure falls as air enters the lungs of the baby with the first breath. This stops the right to left shunting of blood across the atria. As the pressure in the aorta goes above that of pulmonary artery the shunt across ductus arteriosus gets reversed and some blood flows from the aorta into the pulmonary artery. But the ductus arteriosus starts shrinking and functionally closes by about 72 hours of life and anatomically closes within a few weeks. Thus the mixing of blood in the middle of the two sides of the heart completely stops and the usual adult type of blood circulation is established. Another unique highlight of the fetus is the presence of a different type of hemoglobin called fetal hemoglobin. This differs from the adult hemoglobin in that it has higher affinity for oxygen than the adult hemoglobin. Hence it is able to take up hemoglobin from the maternal hemoglobin and deliver it to fetal cells. It can be observed that fetal cells get blood with lower attention of oxygen than adults do because of mixing of blood in the two sides of the heart. The fetus is able to survive in spite of low oxygen attention because the maternal body takes care of many functions and the energy requirement is lower. After birth the attention of fetal hemoglobin falls rapidly and that of adult hemoglobin increases. Thus nature ensures that the fetus develops inside the uterus by getting oxygen from the mom and soon after birth starts utilizing atmospheric oxygen straight through a involved mechanism. It is certainly splendid that for the vast majority of newborns the transition is smooth. I hope you will get new knowledge about Home Delivery. Where you may offer used in your life. And above all, your reaction is passed about Home Delivery. Read more.. Fetal Circulation and Transition To Extra-Uterine Life.