Heart Anatomy and Blood Flow: 12 Key Structures in the Circulatory Circuit

A complete heart diagram traces blood through 12 key structures in sequence:

1. Superior Vena Cava (SVC): Returns deoxygenated blood from upper body → right atrium.
2. Inferior Vena Cava (IVC): Returns deoxygenated blood from lower body → right atrium.
3. Right Atrium: Receives systemic venous return; contains SA node.
4. Tricuspid Valve: 3 leaflets; prevents backflow RA → RV during systole.
5. Right Ventricle: Pumps deoxygenated blood to pulmonary artery (low pressure).
6. Pulmonary Valve: Semilunar; prevents backflow PA → RV.
7. Pulmonary Artery: Only artery carrying deoxygenated blood; splits to L/R lungs.
8. Lungs: Gas exchange (O₂ uptake, CO₂ release) at alveolar capillaries.
9. Pulmonary Veins (4): Carry oxygenated blood → left atrium.
10. Left Atrium: Receives pulmonary venous return.
11. Mitral (Bicuspid) Valve: 2 leaflets; prevents backflow LA → LV.
12. Left Ventricle: Thick-walled; pumps oxygenated blood to aorta (high pressure).
13. Aortic Valve: Semilunar; prevents backflow Ao → LV.
14. Aorta: Distributes oxygenated blood to systemic circulation.

Valves ensure unidirectional flow. Coronary arteries arise from aortic sinuses to supply myocardium.