The bone cortex is the surface structure of the bone as opposed to the bone marrow. In the case of a tubular bone structure such as the femur or humerus, for example, the whole bone is like a water pipe, and the bone cortex is the wall of the water pipe, while the bone marrow is the material in the lumen of the water pipe. The bone cortex is the wall of the water pipe, and the bone marrow is the lumen of the water pipe. The bone cortex is a name used to describe the positioning of the bone in radiographic images of the bone. The bone cortex is the collective name of the periosteum and the bone plate, and the bone plate is the substance of the bone, while the periosteum is distributed on the inner and outer surfaces of the bone plate. When a bone fracture occurs in the human body, a clear image of the fracture of the bone cortex will be seen on the radiograph, and both sides of the bone cortex are fractured at the same time, and the bone cortex appears as a discontinuous radiographic image.