Foramen ovale (heart) ovale, the fossa ovalis. A fetus receives oxygen not from its lungs, but from the mother's oxygen-rich blood via the placenta. Oxygenated blood from the placenta travels through the umbilical cord to the right atrium of the fetal heart. As the fetal lungs are non-functional at this time, it is more efficient for the blood to bypass them. This is accomplished through 2 cardiac shunts. The first is the foramen ovale which shunts blood from the right atrium to the left atrium. The second is the ductus arteriosus which shunts blood from the pulmonary artery (which, after birth, carries blood
Athletic heart syndrome signals the heart to pump more blood through the body to counteract the oxygen deficit building in the skeletal muscles. Enlargement of the heart is a natural physical adaptation of the body to deal with the high pressures and large amounts of blood that can affect the heart during these periods of time. Over time, the body will increase both the chamber size of the left ventricle, and the muscle mass and wall thickness of the heart. Cardiac output, the amount of blood that leaves the heart in a given time period (i.e. liters per minute), is proportional to both