What is the primary role of capillaries in the circulatory system?

The primary role of capillaries in the circulatory system is to connect arteries and veins. Capillaries are tiny blood vessels that facilitate the exchange of gases, nutrients, and waste products between blood and tissues. Their thin walls allow for easy diffusion of substances, which is essential for cellular respiration and maintaining homeostasis.

By linking the arterial system, where oxygen-rich blood is delivered from the heart, to the venous system, where oxygen-poor blood returns to the heart, capillaries play a crucial role in ensuring that tissues receive the oxygen and nutrients they need while also collecting waste products for removal. This connection between arteries and veins underscores the importance of capillaries in the overall functioning of the circulatory system, making them integral to maintaining healthy tissue function and systemic blood circulation.