Heart Chambers and Blood Flow: A Step-by-Step Circuit Guide

Deoxygenated and oxygenated blood follow a precise circuit through the four heart chambers and associated vessels and valves:

1. Superior/Inferior Vena Cava → deliver systemic deoxygenated blood to the Right Atrium.
2. Tricuspid Valve opens → blood flows to Right Ventricle.
3. Pulmonary Valve opens → blood ejected into Pulmonary Arteries → Lungs (gas exchange: CO₂ out, O₂ in).
4. Pulmonary Veins (4) → carry oxygenated blood to Left Atrium.
5. Mitral Valve opens → blood flows to Left Ventricle.
6. Aortic Valve opens → blood ejected into Aorta → systemic circulation.

Valves ensure unidirectional flow. The left ventricle generates higher pressure (systemic circulation) than the right (pulmonary circulation).