what are the adaptations in the fetal circulation?

Answer 1

Throughout the fetal stage of development, the maternal blood supplies the fetus with O2 and nutrients and carries away its wastes.
These substances diffuse between the maternal and fetal blood through the placental membrane.
They are carried to and from the fetal body by the umbilical blood vessels.
Adaptations of fetal blood and vascular system.
The concentration of hemoglobin in fetal blood is about 50 % greater than in maternal blood.
Fetal hemoglobin is slightly different chemically and has a greater affinity for O2 than maternal hemoglobin.
At a particular oxygen partial pressure, fetal hemoglobin can carry 20-30% more O2 than maternal hemoglobin.

Fetal Circulation OH-98

In the fetal circulatory system, the umbilical vein transports blood rich in O2 and nutrients from the placenta to the fetal body.
The umbilical vein enters the body through the umbilical ring and travels along the anterior abdominal wall to the liver.
About 1/2 the blood it carries passes into the liver.
The other 1/2 of the blood enters a vessel called the ductus venosus which bypasses the liver.
The ductus venosus travels a short distance and joins the inferior vena cava.
There, the oxygenated blood from the placenta is mixed with the deoxygenated blood from the lower parts of the body.
This mixture continues through the vena cava to the right atrium.
In the adult heart, blood flows from the right atrium to the right ventricle then through the pulmonary arteries to the lungs.
In the fetus however, the lungs are nonfunctional and the blood largely bypasses them.
As the blood from the inferior vena cava enters the right atrium, a large proportion of it is shunted directly into the left atrium through an opening called the foramen ovale.
A small valve, septum primum is located on the left side of the atrial septum overlies the foramen ovale and helps prevent blood from moving in the reverse direction.
The rest of the fetal blood entering the right atrium, including a large proportion of the deoxygenated blood entering from the superior vena cava passes into the right ventricle and out through the pulmonary trunk.
Only a small volume of blood enters the pulmonary circuit, because the lungs are collapsed, and their blood vessels have a high resistance to flow.
Enough blood reaches the lung tissue to sustain them.
Most of the blood in the pulmonary trunk bypasses the lungs by entering a fetal vessel called the ductus arteriosus which connects the pulmonary trunk to the descending portion of the aortic arch.
As a result of this connection, the blood with a relatively low O2 concentration which is returning to the heart through the superior vena cava, bypasses the lungs.
At the same time, the blood is prevented from entering the portion of the aorta that provides branches leading to the brain.
The more highly oxygenated blood that enters the left atrium through the foramen ovale is mixed with a small amount of deoxygenated blood returning from the pulmonary veins.
This mixture moves into the left ventricle and is pumped into the aorta.
Some of it reaches the myocardium through the coronary arteries and some reaches the brain through the carotid arteries.
The blood carried by the descending aorta is partially oxygenated and partially deoxygenated.
Some of it is carries into the branches of the aorta that lead to various parts of the lower regions of the body.
The rest passes into the umbilical arteries, which branch from the internal iliac arteries and lead to the placenta.
There the blood is reoxygenated.

Answer 2

The blood from the placenta enters one million. the umbilical vein and passes by means of 2. the porta hepatis into the inferior vena cava. The blood then flows into the final atrium the place this column of blood is principally flowing from the final to the left and ordinarily passes interior the direction of the three. foramen ovale into the left atrium and interior the direction of the mitral valve into the left ventricle and out the aortic valve to the ascending aorta. maximum of this blood flow (the greater oxygen wealthy) flows to the better physique which includes the recommendations. Blood returns from the better physique by utilizing way of the better vena cava and is flowing specially from top to backside whilst it enters suitable atrium and this column of flow specially passes into the tricuspid valve into the final ventricle. The blood leaves the final ventricle by utilizing way of the pulmonary valve into the pulmonary artery. because of the fact the lungs at the instant are not more suitable, the tremendous majority of the flow passes interior the direction of the 4. ductus arteriosis into the descending aorta (serving the decrease physique) and out the 5. umbilical arteries to the placenta.

Answer 3

Yup, he's exactly right.