Blood Vessels – Arteries and Veins
- Blood vessels are a network of branched tubes that transport blood.
- There are three types of blood vessels namely arteries, veins and capillaries
Arteries:
- They are thick and elastic vessels that carry blood away from the heart to various organs of the body.
- All arteries carry oxygenated blood except the pulmonary artery which carry deoxygenated blood to the lungs.
Veins:
- Veins are thin and non-elastic vessels that transport blood to the heart from the different organs.
- All veins carry deoxygenated blood except the pulmonary vein which carry oxygenated blood from the lungs to the heart.
Capillaries:
- Capillaries are narrow tubes formed by branching of arterioles which then unite to form the venules and veins.
- They are about 8 µm in diameter.
- Capillaries are formed of single layer of endothelial cells.