The median bones include the skull and trunk bones. The median bone is the core part of the human skeleton and can mainly play the role of support, protection and movement. In addition to this, the bone marrow of the median bone has an important role in the body’s hematopoietic function. Among the minors, most of the bones in the human body contain red bone marrow, and after the growth and development, the bone marrow of the limbs turns into yellow bone marrow and loses its hematopoietic function. The red bone marrow in the median bone is still preserved and can continue to maintain the hematopoietic function.1. Cranial bone: The cranial bone refers to all the bones of the human head and face, and its composition is divided into cerebral cranial bone and facial cranial bone. In this, the brain and skull together form the cranial cavity of the human body, which has the brain and related nerves inside. The facial skull is responsible for forming the body’s facial contour scaffolding, providing a scaffold for the attachment of teeth, and constitutes the temporomandibular joint, so that the body can open its mouth; 2, trunk bone: trunk bone refers to the human body in the trunk internal bone, including the various parts of the human spine and the thoracic part of the sternum and rib cage. The human spine is composed of the cervical, thoracic, lumbar, and sacral and caudal vertebrae, respectively. In adults, the spine has seven cervical vertebrae, 12 thoracic vertebrae, five lumbar vertebrae, and one sacral and one caudal vertebrae. Before the end of human growth and development, there are 4 sacral vertebrae and 4-5 caudal vertebrae, and the connections between the bones are not yet ossified. In the area of the thorax, there are 12 ribs on each side of it and 1 sternum in the front. The ribs form a joint with the thoracic vertebrae in the back and are connected to the sternum in the front, and the ribs, sternum and thoracic vertebrae together form the human thorax.