The smallest blood vessels in the body are called capillaries. They are so small that about ten of them would equal the thickness of a human hair. In fact, most capillaries are so narrow that only one red blood cell can pass through at a time.
Capillaries play a crucial role in the circulatory system by connecting the arteries, which carry blood away from the heart, to the veins, which return blood to the heart. This intricate network of tiny vessels facilitates the exchange of oxygen, nutrients, and waste products between the blood and the surrounding tissues.
Here are some additional details about capillaries:
- Structure: Capillaries have thin walls composed of a single layer of endothelial cells, which allows for efficient diffusion of substances.
- Function: They act as the primary site for the exchange of gases, nutrients, and waste products between the blood and tissues.
- Location: Capillaries are found throughout the body, forming intricate networks within organs and tissues.
