What is the name of the shaft of a long bone?

The shaft of a long bone is referred to as the diaphysis. This term specifically describes the elongated, tubular section that makes up the majority of a long bone's structure. The diaphysis is composed primarily of compact bone, which provides strength and stability, and it houses the medullary cavity, where bone marrow is stored.

In contrast, the epiphysis refers to the ends of the long bone, which articulate with other bones and are typically covered by articular cartilage to facilitate smooth movement at joints. The metaphysis is the region between the diaphysis and the epiphysis, where growth plates (or epiphyseal plates) are located in growing bones. Lastly, the periosteum is a dense layer of vascular connective tissue that envelops the bones, except at their surfaces, providing attachment for muscles and tendons and playing a role in bone repair and growth. Understanding these distinctions is crucial for anyone working in orthopedics or related fields.