The skeletal system is the internal framework of the human body, consisting of bones, cartilage, ligaments, and tendons. It provides the body with structure, support, and protection for organs, and allows for movement. The human skeleton is composed of around 206 bones by adulthood after some bones get fused together. The bone mass in the skeleton makes up about 14% of the total body weight and reaches maximum mass between the ages of 25 and 30. The human skeleton can be divided into two main parts: the axial skeleton and the appendicular skeleton.

The axial skeleton is formed by the vertebral column, the rib cage, the skull, and other associated bones. It consists of 80 bones, including the vertebral column, a part of the rib cage, and the skull. The appendicular skeleton consists of the bones that make up the arms and legs, as well as the bones that attach them to the axial skeleton. It consists of 126 bones, including the pectoral girdle, the pelvic girdle, the upper limbs, and the lower limbs.

The skeletal system also produces blood cells, stores minerals, and provides attachments and anchorage to muscles and ligaments and joint capsules. Bones contain more calcium than any other organ, and the intercellular matrix of bone contains large amounts of calcium salts, the most important being calcium phosphate. When blood calcium levels decrease below normal, calcium is released from the bones so that there will be an adequate supply for metabolic needs.

The skeletal system is essential for maintaining overall health and well-being. To keep the skeletal system strong and healthy, it is important to maintain a healthy diet, exercise regularly, and avoid smoking and excessive alcohol consumption.