Concept:
Double circulation is the process in which blood passes through the heart twice during one complete cycle — once through pulmonary circulation and once through systemic circulation.
Steps in Double Circulation:1. Pulmonary Circulation (Heart → Lungs → Heart):
Deoxygenated blood from the body enters the right atrium through the superior and inferior vena cava.
Blood flows from the right atrium to the right ventricle.
The right ventricle pumps blood to the lungs through the pulmonary artery.
In the lungs, carbon dioxide is exchanged for oxygen.
Oxygenated blood returns to the left atrium through the pulmonary veins.
2. Systemic Circulation (Heart → Body → Heart):
Oxygenated blood moves from the left atrium to the left ventricle.
The left ventricle pumps blood to the entire body through the aorta.
Body cells use oxygen and release carbon dioxide.
Deoxygenated blood returns to the right atrium through veins.
Conclusion:
In double circulation, blood flows through the heart twice in one complete cycle — ensuring efficient oxygen supply and separation of oxygenated and deoxygenated blood.