The heart is the first organ to receive freshly oxygenated blood from the lungs, explains the National Institute of Health. The heart has two sides. The right side pumps blood to the lungs to pick up oxygen and the left side of the heart receives the blood immediately after oxygenation.
The oxygen-rich blood from the lungs returns to the heart via the right and left pulmonary veins, dumping into the left atrium. The NIH explains that the blood moves from the left atrium to the left ventricle chamber, where it is pumped out of the heart through the aortic valve. The aorta is the main artery that carries oxygen-rich blood from the left side of the heart to the body. Also connected to the aorta are coronary arteries, which flow to the muscles of the heart. This network of coronary arteries provides the heart muscles with their own necessary supply of oxygen-rich blood, explains NIH.