The system made up of bone and cartilage derived from the embryonic mesoderm that forms the body structure, carries the weight of the body, attaches muscles and protects the soft parts of the body is called the skeletal system. It is made up of 206 bones. The skeletal system accounts for 15% and 10% of the total body weight of men and women respectively. Volatility density is highest at 21 years of age. The branch of biology that deals with human bones is called osteology or human osteology.