1. Blood vessels are classified into three distinct types: arteries, veins, and capillaries.

Arteries

1. Arteries are blood vessels that carry oxygen-rich blood from the heart to the body’s tissues.
2. Arteries branch several times into smaller arterioles as they carry blood farther from the heart and into the organs.

Vein

1. Veins are the blood vessels that carry blood back from the body tissues to the heart. Veins bring back the deoxygenated blood to the heart after arteries carry blood out.
2. Veins situated closer to the heart are larger in size.
3. The superior vena cava is a large vein present in the upper half of the body, and it carries blood from the head and arms to the heart.
4. The inferior vena cava carries the blood from the abdominal region and legs back to the heart.

Capillary

1. Capillaries are the small and thin blood vessels that it is permeable to the oxygen and nutrients carried by the blood.
2. They connect arteries and veins.
3. They have thin walls allowing oxygen, nutrients, carbon dioxide, and other waste products to pass to and from cells.