The human body has 206 bones, which are divided into three parts: skull, trunk and limbs. There are 29 skulls, 5 trunk bones1and 4 femurs 126.

There are 29 skulls, 5 trunk bones1and 4 femurs 126. Typical adult bones include the following 206? A bone.

Generally, it can be divided into four forms: long bone, short bone, flat bone and irregular bone:

1, long bone

The body is long and hard, distributed in people's limbs, and plays a leverage role in sports. Long bones are mostly tubular with cavities and marrow, such as femur, tibia, humerus, ulna, flexor and phalanx.

2. Short bones

Shaped like a cube and full of pressure, they are usually connected together in clusters, and most of them are located in complex parts that move under pressure, such as the wrist bone of the wrist and the tarsal bone of the ankle.

3. Flat bone

Most of them are plate-shaped, elastic and strong, which mainly constitute the wall of bone cavity and protect the organs in the cavity. Such as the parietal bone, occipital bone and ribs in the skull.

4. Irregular bone

The shape is very irregular and does not belong to any of the above bones. Such as hip bones, vertebrae, temporal bones, etc.

Extended data:

The role of bones:

1. Support function: Different bones of the human body are connected into a whole through joints, muscles, ligaments and other tissues to 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 up, let alone walk.

2. Protection function: The human skeleton is like a frame, which protects the important organs of the human body and avoids 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 pelvis protects the bladder and uterus. 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 to realize the motor function of human body. Bones provide necessary support for exercise, muscles and tendons provide power for exercise, and ligaments are used to maintain the stability of bones and enable exercise to continue. So we say that bones are the basis of exercise.

4. Metabolic function: Bone is closely related to human metabolism. Bone contains a lot of organic and inorganic substances such as calcium and phosphorus, and is a participant and regulator of inorganic salt metabolism in the body. Bone is also involved in the regulation of human endocrine, affecting the secretion and metabolism of hormones in the body. Bone is 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.

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