Why is blood pumped to the lungs before it round body?

This statement isn't entirely accurate. While blood does flow to the lungs before it circulates throughout the rest of the body, it doesn't skip going to the rest of the body. Our circulatory system is a continuous loop.

Here's a simplified explanation of how the circulatory system works:

1. Pulmonary Circulation: The heart pumps deoxygenated blood from the right atrium to the right ventricle. The right ventricle then pumps the blood to the lungs through the pulmonary arteries.

2. Gas Exchange: In the lungs, the blood releases carbon dioxide and picks up oxygen. This oxygen-rich blood now flows back to the heart through the pulmonary veins.

3. Systemic Circulation: The oxygen-rich blood from the lungs enters the left atrium of the heart. The left ventricle pumps this blood out to the rest of the body through the aorta, the main artery.

4. Oxygen Delivery: The arteries branch out into smaller vessels called capillaries, where the oxygen and nutrients are delivered to the body's tissues.

5. Deoxygenated Blood Return: The capillaries collect the deoxygenated blood, which contains waste products like carbon dioxide. This blood flows into small veins, which merge to form larger veins. These veins carry the deoxygenated blood back to the right atrium, completing the circuit.

So, while blood does first go to the lungs to pick up oxygen before it circulates throughout the body, it is a continuous process where blood flows out of the heart, to the lungs, back to the heart, and then out to the body, and then returns to the heart.