What structures in the body rely on capillaries?

Capillaries are crucial for various structures in the body, particularly in organs such as the lungs, kidneys, and muscles. They facilitate the exchange of oxygen, carbon dioxide, nutrients, and waste products between blood and surrounding tissues. In the lungs, capillaries enable gas exchange, while in the kidneys, they play a key role in filtration and waste removal. Additionally, capillaries supply nourishment to every cell in the body through their extensive network.