A microscopic blood vessel connecting arteries to veins. The blood constituents seep through these tiny vessels in the systemic (body) circulation and pulmonary (lung) circulation. Their walls are extremely thin and allow oxygen, carbon dioxide, glucose and other chemicals to pass to and fro between the blood and the surrounding cells in the body organs, or air sacs in the lungs.
« Back to Glossary IndexCapillary
« Back to Glossary Index