Deoxygenated blood from the body via the vena cava enters the right atrium of the heart. the right atrium pumps the blood via the trucuspid valve into the right ventricle. From the right ventricle, blood is pumped into the pulmonary trunk via the pulmonic valve to the lungs. Oxygenated blood from the lungs enters the left atrium via the pulmonary veins. The left atrium pumps the blood to the left ventricle via the mitral valve. The left ventricle pumps this blood via the aortic valve to the aorta which distribute the blood to the rest of the body
Vena cava - right atrium - tricuspid valve - right ventricle - pulmonary artery/trunk - lungs - pulmonary veins - left atrium - mitral valve - left ventricle - aortic valve - aorta - rest of body.