What is the difference between veins, arteries and capillaries?
Veins carry blood to the heart, arteries from the heart, and capillaries link the two.
Arteries carry blood under high pressure from the heart to the organs and tissues. Their walls are generally thicker than veins.
All arteries except the pulmonary arteries carry oxygenated blood.
Veins carry blood under low pressure from the organs and tissues back to the heart. Their walls are thinner generally.
All veins except the pulmonary veins carry deoxygenated blood.
Capillaries are the link between arteries and veins and are very small, Tissue fluid sometimes seeps out and is recollected by the lymphatic system and returned to the veins.