Capillary blood vessels are the smallest and most numerous blood vessels in the body. They connect arteries and veins, allowing for the exchange of oxygen, nutrients, and waste products between the blood and surrounding tissues. Their thin walls, made of a single layer of cells, facilitate this exchange efficiently. These tiny vessels are crucial for maintaining healthy tissue function. The extensive network of capillaries ensures that every cell receives the necessary substances for survival while removing waste. This process is vital for overall health and is essential for the proper functioning of organs and systems throughout the body.