The shift in pressure stimulates the foramen ovale to close. They also lower the pressure in the right atrium. These changes raise the pressure in the left atrium of the heart. An increase in the baby's blood pressure and a major reduction in the pulmonary pressures reduce the need for the ductus arteriosus to shunt blood. As the lungs expand, the alveoli in the lungs are cleared of fluid. With the first breaths of life, the lungs start to expand. Among them, coronary artery disease (CAD) is the most important disease in terms of. Oxygen and nutrients from the mother's blood are released into the fetus' blood.Īt birth, the umbilical cord is clamped and the baby no longer gets oxygen and nutrients from the mother. CVDs are a cluster of disorders that involve heart and blood vessels. In the placenta, carbon dioxide and waste products are released into the mother's circulatory system. This blood then enters the umbilical arteries and flows into the placenta. Most of this blood is shunted through the ductus arteriosus to the descending aorta. A small amount of the blood continues on to the lungs. This less oxygenated blood is pumped from the right ventricle into the pulmonary artery. Instead of going back through the foramen ovale, it goes into the right ventricle. Very little of this less oxygenated blood mixes with the oxygenated blood. After circulating there, the blood returns to the right atrium of the heart through the superior vena cava. This is the large artery coming from the heart.įrom the aorta, blood is sent to the heart muscle itself and to the brain and arms. When the blood enters the right atrium, most of it flows through the foramen ovale into the left atrium.īlood then passes into the left ventricle. This is the chamber on the upper right side of the heart. Four valves regulate blood flow through your heart: The tricuspid valve regulates blood flow between the right atrium and right ventricle. Inside the fetal heartīlood enters the right atrium. Waste products from the fetal blood are transferred back across the placenta to the mother's blood. A small amount of this blood goes straight to the liver to give it the oxygen and nutrients it needs. 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. Most of this blood is sent through the ductus venosus. This is a major vein connected to the heart. The blood then reaches the inferior vena cava. The enriched blood flows through the umbilical cord to the liver and splits into 3 branches. Oxygen and nutrients from the mother's blood are sent across the placenta to the fetus. The ductus arteriosus moves blood from the pulmonary artery to the aorta. This shunt moves blood from the right atrium of the heart to the left atrium. The shunt that bypasses the lungs is called the foramen ovale. That's because these organs will not work fully until after birth. The purpose of these shunts is to bypass the lungs and liver. These are small passages that direct blood that needs to be oxygenated. See the Labelling the heart activity for additional support in using this interactive.The fetal circulatory system uses 3 shunts. Selecting or hovering over a box will highlight each area in the diagram.įor optimal viewing of this interactive, view at your screen’s default zoom setting (100%) and with your browser window view maximised. Use Reset All to practise again from the start. When you are happy with your selection, use the Check answers button to check them. If you want to check your answers, use the Reset Incorrect button. The process of moving blood through the body is called circulation. If you want to redo an answer, click on the box and the answer will go back to the top so you can move it to another box. Blood is carried through the body in blood vessels, or tubes, called arteries and veins. Drag and drop the text labels onto the boxes next to the heart diagram. In this interactive, you can label parts of the human heart.

Heart blood flow diagram