What are capillaries?
1 Answer
Capillaries are the fine tubules linking arterioles and venules in a network that enable the exchange of nutrients between blood and tissues.
Explanation:
Oxygenated blood is transported from the heart via the aorta which divides and subdivides into arteries and arterioles that branch into every part of the body. At the tissue level, arterioles end in a fine network of tubules called capillaries that have a single-celled endothelial layer.
These capillaries then reconnect with venules that combine to form veins and further combine into the superior and inferior venae cavae that carry de-oxygenated blood back to the heart.
The thin lining of the capillary walls enables the exchange of water, nutrients and oxygen between the blood and tissues as well as the collection of carbon dioxide and waste substances.
