Circulatory System

• The heart has four chambers: two atria and two ventricles.
• The heart is located between the lungs, behind the sternum (breastbone), and to the left side of the body.
• Blood flows from the right atrium into the right ventricle through the tricuspid valve.
• Blood flows from the right side to the left side of the heart through the pulmonary valve, which separates the right ventricle from the pulmonary artery.
• Oxygenated blood enters the left atrium through the pulmonary vein.
• Deoxygenated blood leaves the right ventricle through the pulmonary artery.
• Blood flows from the left atrium into the left ventricle through the bicuspid valve.
• Blood then leaves the right ventricle through the pulmonary semilunar valve and enters the pulmonary trunk.
• Pulmonary trunk divides into the right and left pulmonary arteries that carry blood to the lungs.
• Valves prevent backflow of blood during contraction of the ventricles.
• Blood then passes through the bicuspid or mitral valve into the left ventricle.
• Blood flows from the left atrium into the left ventricle through the bicuspid or mitral valve.
• From the left ventricle, oxygen-rich blood exits the heart via the aortic semilunar valve and travels throughout the body.
• Blood flows out of the left ventricle through the aortic semilunar valve, which leads to the aorta.
• The heart's electrical system controls its rhythm and coordination.
• In the lungs, carbon dioxide is removed from the bloodstream and oxygen diffuses into it.
• Arterioles are small arteries with smooth muscle walls that can constrict or dilate depending on demand.
• The heart is divided into four chambers, two atria (right and left) and two ventricles (right and left).