The depiction of an event late in the game was inspired by Crisis Core: Final Fantasy VII, a storyline tying into the opening of Final Fantasy VII. Ifrit's throne resembles the throne Chaos sits in in a concept art piece by Yoshitaka Amano. for the original Final Fantasy.
The blood first enters the heart into the right atrium. Blood passes from the right atrium through the tricuspid valve and into the right ventricle. When the right ventricle contracts, the muscular force pushes blood through the pulmonary semilunar valve into the pulmonary artery. The blood then travels to the lungs, where it receives oxygen. Next, it drains out of the lungs via the pulmonary veins, and travels to the left atrium.
The pulmonary arteries send blood to the lungs to become oxygenated. It is then circulated throughout the body in a process known as respiration. The pulmonary arteries send blood to the lungs to become oxygenated.