The musculoskeletal system is formed by skeletal bones, joints, cartilages, muscles and ligaments. Bones consist of a spongy and compact substance, periosteum and endosteum, as well as a bone marrow canal in tubular bones and bone marrow lacunae of flat bones. Mature bone tissue has a mineralized and nonmineralized matrix (osteoid). There are two main cell lines in the bone: those synthesizing cells (osteoblasts) and those breaking down cells (osteoclasts), which provides a balance between the synthesis and resorption of bone tissue. Osteocytes are located in bone cavities, or lacunae; these are flat cells whose function is to preserve the bone matrix and its mineral composition.
Diseases of the musculoskeletal system are divided into the following groups: diseases caused by genetic disorders (dysplasia), metabolic diseases of bone tissue, infectious bone diseases, bone tumors, skeletal bone injuries, joint diseases, disorders of the musculoligamentous apparatus.