1. Support and Protection
2. Body Movement
3. Blood cell formation: The formation of blood is called hematopiesis, begins in the yolk sac, later, the blood cells are manufactured in the liver, spleen, and in the bone marrow. There are two kinds of bone marrow: yellow marrow, and red marrow. Red Marrow produces the red blood cells, white blood cells, and platelets. The yellow marrow stores fat.
4. Inorganic salt storage: Bone tissue stores large amounts of calcium, phosphorus, but small amounts of magnesium, sodium, potassium, and carbonate ion.