What system in the fetus is bypassed by fetal 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.
What is it in the fetal circulation that allows blood to bypass the liver?
Most of this blood is sent through the ductus venosus. This is also a shunt that lets highly oxygenated blood bypass the liver to the inferior vena cava and then to the right atrium of the heart.
Where does blood bypass the fetal lungs by?
In the fetus, the placenta does the work of breathing instead of the lungs. As a result, only a small amount of the blood continues on to the lungs. Most of this blood is bypassed or shunted away from the lungs through the ductus arteriosus to the aorta.
What tube allows fetal blood to bypass the heart all together?
The ductus arteriosus is the conduit for fetal blood to bypass the lungs in utero. The ductus usually closes in the first days of life. If it does not close, as pulmonary vascular resistance falls, blood shunts from the aorta into the pulmonary artery (Fig. 83-11).
What is fetal blood circulation?
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.
Which fetal circulatory structure shunts blood from the pulmonary trunk to the aorta?
ductus arteriosus
The shunt that bypasses the lungs is called the foramen ovale. This shunt moves blood from the right atrium of the heart to the left atrium. The ductus arteriosus moves blood from the pulmonary artery to the aorta. Oxygen and nutrients from the mother’s blood are sent across the placenta to the fetus.
Why does fetal blood bypass the liver?
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.
What is the name of the structure that allows blood flow between the right and left atrium?
These valves ensure that blood flows in only one direction, preventing backflow. The tricuspid valve is situated between the right atrium and right ventricle. The pulmonary valve is between the right ventricle and the pulmonary artery. The mitral valve is between the left atrium and left ventricle.
Where does the umbilical vein enter the circulation of the fetus?
liver
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 Interatrial opening allows blood entering the fetal right atrium to bypass the pulmonary circuit?
[1] In turn, the foramen ovale is the primary shunt to circumvent blood away from the lungs. The blood can pass through the right atrium and enter the left atrium through the foramen ovale through a pressure gradient.
Is fetal circulation in series or parallel?
Fetal circulation functions as a parallel circuit, where both the right and left sides of the heart provide systemic blood flow. (Figure 2-1) Thus, cardiac output (450 mL/kg/min) in the fetus is the sum of both the right and left ventricular outputs.