The number of bones in the human body is actually fixed, the number of bones in adults is 206, according to the parts for divided into the skull of the head, the trunk bones of the body and limbs of the limbs, the number of bones in these three major parts are also fixed, and ligaments connected together, this state can have different bone changes in the situation. In addition, bones can also be distinguished by morphological help, divided into long bones, short bones, flat bones, irregular bones and so on. There are more bones in children than in adults, the sacrum is 5 pieces and only becomes 1 piece after healing, there may be more than in adults, so the bones of the human body are mainly related to the distinction between adults and children.