Most people think of bones as being rigid, immobile structures that hold up our bodies. However, we often forget that they are living tissue that performs many vital functions for the body. In addition to supporting the body, bones provide a framework for movement, protect the brain and organs from injury, store minerals and fat, and produce bone marrow, which produces blood cells.
The bones of the skull and ribcage protect the brain and lungs, while the spine provides protection for the spinal cord and vertebrae. Other bones protect internal organs such as the liver, kidneys, and stomach. Bones are also a reservoir for calcium and other minerals, which are released when the bones need them.
In order to meet the body's ever-changing needs, the bones continually remodel and reshape themselves. This process is called skeletal remodeling and it is a continuous cellular, mineral and metabolic event that continues throughout life unless halted by external forces or internal abnormalities such as trauma or disease.
Skeletal muscle is a type of contractile tissue that functions to move the bones and body parts. This type of muscle is striated and nonstriated and contains multinucleate muscle fibers. Muscles are attached to bones by way of tendons (tuh-NO-ses).
The main function of skeletal muscle is to produce traction, which pulls muscles against the bones they attach to. Other functions include maintaining posture, movement, and joint stability. Muscles also play a role in blood formation and muscle communication with the nervous system. Regular exercise and a healthy diet can help you maintain strong, flexible bones and joints for your whole life.