Firstly, the right atrium gets deoxygenated blood from the rest of the body. Afterwards, the blood flows into right ventricle over the tricuspid valve, as soon as the right ventricle contracts the tricuspid valve closes and blood ejected into the pulmonary artery. Later on, the pulmonary trunk divides into the right and left pulmonary artery, which carries blood to the lungs where gas, makes exchange. Once oxygenated blood flows from vessels into pulmonary veins where it plumbing into the left atrium. After that, blood flows from the left atrium into the left ventricle through the mitral valve. Finally, from the mitral valve the oxygenated blood goes into the aorta to go all the way down to the body.
(InSlideshare)