The Human Heart and Circulation

The Heart

The heart is a muscular organ that pumps blood around the body. It has four chambers: two atria at the top and two ventricles at the bottom.

Blood Vessels

• Arteries carry blood away from the heart.
• Veins carry blood back to the heart.
• Capillaries are tiny vessels where exchange of gases and nutrients happens.

Circulation

Blood carries oxygen and food to all body cells and removes waste such as carbon dioxide. The heart keeps this flow going day and night.

Key Points

A healthy diet and regular exercise keep the heart strong.