Capillaries are very small blood vessels that carry blood to all parts of the body.
Veins are blood vessels that carry blood to the heart.
Arteries are large blood vessels that carry blood away from the heart. Plasma is the fluid portion of the blood that carries nutrients. Red blood cells give color to the blood and carry oxygen. White blood cells defend the body against infection and attack foreign particles. Platelets are disk shaped and assist in clotting the blood, the mechanism that stops bleeding.