How does blood flow through the heart?

(First would talk through the structure of the heart using a diagram).
Deoxygenated (lacking oxygen) blood from the body arrives into the heart via the vena cava. This empties into the right atrium and then travels through the open tricuspid valve into the right ventricle. Blood then passes into the pulmonary artery to then travel to the lungs to pick up oxygen. This newly oxygenated blood travels back to the heart through pulmonary veins that then empty into the left atrium. Then, the blood passes through the open bicuspid valve into the left ventricle. Lastly, the oxygenated blood enters the aorta and is then pumped to the rest of the body.
This demonstrates a double circulatory system in the human body. One circuit is known as the pulmonary circuit between the heart and the lungs and the other is known as the systemic circuit between the heart and the other organs.