Bones

Bone serves many important functions. Bones support the body, protect underlying organs, and provide a movable skeleton against which the muscles can work. In addition, bone forms all the cells of the blood, plus takes part in calcium and acid-base balance, and storage of trace elements (such as zinc) needed by cells elsewhere. bone as the most lasting parts of the body, bones are traditionally used for ‘mortal remains’. The longest bone is the femur (thigh bone), which accounts for a quarter of one's stature; the smallest bone is the stapes — one of the tiny ossicles in the middle ear which transmits the vibrations from the ear drum to the inner ear. There are over 200 bones in the adult skeleton. They can be divided into two principal types: the long bones such as the femur, tibia, and humerus, which develop principally from within a cartilaginous framework, and the flat bones such as the skull, bones of the pelvis, and scapula, which develop within membranes of fibrous tissue.

Intervertebral disc

A intervertebral disc disorder is a condition that involves deterioration, herniation, or other dysfunction of an intervertebral disc.
As people age, the nucleus pulposus begins to dehydrate, which limits its ability to transfer and distribute loads between the vertebrae. These loads are instead transferred non-uniformly through the annulus fibrosus, which undergoes progressive, structural deterioration. While this may not cause pain in some people, in others one or both of these may cause chronic pain.