There are 206 human bones for adults and 2 18 for children. There are 206 bones in adult's skeleton, including skull, trunk and limbs. Among them, there are 29 skulls, 5 trunk bones1and 4 limbs bones 126.

The shapes of bones are long bones, short bones, flat bones and irregular bones. There are 2 18 bones in children, which gradually differentiate into one bone after adulthood. For example, there are 5 bones in sacrum, and they merge into 1 block after adulthood. There are sesamoids in some places, which will increase accordingly. Skeleton has support, protects human organs and tissues, and has hematopoietic and motor functions.

The role of human bones:

1, supporting function: different bones of human body are connected into a whole through joints, muscles, ligaments and other tissues, which support the body. If human beings have no bones, they can only be a pile of soft tissues lying on the ground, and they can't stand, let alone walk.

2. Protective function: The human skeleton is like a frame, which protects the important organs of the human body, so as to avoid the "scratch" and damage of external forces as much as possible. For example, the skull protects the brain tissue, the spine and ribs protect the heart and lungs, and the pelvic bones protect the bladder. Without the protection of bones, external shocks and blows can easily damage internal organs.

3. Motor function: Bones cooperate with muscles, tendons, ligaments and other tissues, and * * * has the same motor function. The necessary support of bone movement, the motive force of muscle and tendon movement, and the role of ligament are to maintain the stability of bone and make the movement continue. Therefore, we say that bones are the basis of exercise.

4. Metabolic function: There is a close relationship between bones and human metabolism. Bone contains a lot of calcium, phosphorus and other organic and inorganic substances, and is a participant and regulator of inorganic salt metabolism in the body. Bones are also related to electrolyte balance in the body.

5. Hematopoietic function: The hematopoietic function of bones is mainly manifested in human childhood, and the bone marrow cavity contains a large number of hematopoietic cells, which participate in the formation of blood. When people reach adulthood, red bone marrow with hematopoietic function still exists in some cancellous bones.