Functions of Bones

Bones form an important component of the skeletal system. They perform a wide range of important functions that can be classified into three categories:

Mechanical Functions of bones:

  • Protection:
    At numerous places inside the body, bones serve to protect important and delicate organs. The best examples to be quoted here are those of brain (which is protected by the skull) and heart (which is protected by the ribcage).
  • Shape:
    Because of their rigid nature, bones provide a framework around which the body is built. So bones are responsible for the shape and form of human body.
  • Movement:
    Working with skeletal muscles, tendons, ligaments and joints, the bones form the moving machinery of human body. The major role of bones in movement is that they act as levers, which make use of the forces generated by skeletal muscles in a beneficial way.

Synthetic Functions of Bones:

  • Synthesis of blood cells:
    The major synthetic role of bones is to produce blood cells. The bones themselves are not capable of doing this. Instead, they house the bone marrow, which contains Hematopoietic stem cells, capable of producing blood cells. In infants, bone marrow of all long bones is capable of this synthesis, however, as a person gets older, the red marrow turns into yellow fatty marrow, which is no more capable of hematopoiesis. The red marrow in adults and older individuals is restricted to vertebrae and heads of tibia and femur.

Metabolic Functions of Bones:

  • Mineral Storage:
    Bones serve as an important store house of minerals such as calcium and phosphorus.
  • Fat storage:
    The yellow bone marrow of long bones act as a storage of fats.
  • Role in acid-base balance:
    Bone buffers the blood against excessive pH changes by absorbing or releasing alkaline salts