Leukocytes consist of various

 Leukocytes consist of various constituent cells (neutrophils, eosinophils, basophils, lymphocytes, monocytes), which has the function of preventing the disease.
    Phagocytosis (eating cells that have been damaged or dead). Cells that perform phagocytosis called phagocytes. Examples of phagocytes include Granulocytes, monocytes and T-lymphocytes.

. Prevention intruding germs. Through the mechanism of blood clotting
3. Regulate acid-base balance (pH) of blood.
4. Regulate body temperature.

    Blood has the ability to regulate body temperature, because the water contained in the blood have 3 kinds of properties suitable for this purpose are relatively high specific heat of water (the amount of calories needed to raise 1 C 1 kg of the substance).
5. Prevent bleeding.
6. Regulate fluid balance between the blood with tissue fluid.
The tool blood circulation• Tools that serve to circulate blood throughout the human body include:
1. Blood vessel

    The blood vessels are closed canal system that brought blood from the heart to all parts of the body and back to the heart.
    Blood out and back through the heart of the two distribution are:
    Pulmonary circulation: blood through the pulmonary artery into the pulmonaria and back to the heart through a vein Pulmonaris
    Systemic circulation: the blood out through the aorta to the body and back through the heart of the superior and inferior vena cava and cardiac veins