Besides being the base structure of the body in skeletal form, bones, along with joints and muscles, determine the range of motion for joints, the force that can be produced and the specific movement allowed in the body. The skeletal system is made up of three parts, all of which are necessary for normal function and protection.
Skeletal System
The skeletal system consists of osseous or bone tissue, cartilage and periosteum. The bones support soft tissue, protect internal organs and help transport important nutrients through the body. The American College of Sports Medicine defines cartilage as a resilient, semirigid form of connective tissue that reduces friction and absorbs some shock in joints. The periosteum is a membrane covering bones, which serves as a point of attachment for not only ligaments but tendons as well.
Bone Physiology
Besides supporting, protecting and aiding in movement of the body, bones also store several minerals and alternative energy, and produce red blood cells. Bones can distribute minerals to other parts of the body on demand, as well as red blood cells in a process called hemopoiesis. Yellow marrow, one of the two types of marrow in the bones -- red being the other -- contains adipose cells that can be used as an energy source when needed.
Histology
Mesenchyme, the tissue from which all connective tissue is derived, forms osteoprogenitor, which can divide and multiply. When this occurs, osteoblasts are formed. The main task of osteoblasts is to form new bone when the diaphysis, the long shaft of the bone, undergoes a disturbance. Osteocytes are matured osteoblasts and are called the principle cells of bone tissue. Osteoclasts originating from white blood cells settle on the surface of bone to provide proper development, growth, maintenance and repair of bone.
Bone Health
Crystallized bone, called hydroxyapatite, contains nutrients and minerals, including salts, calcium, magnesium hydroxide, fluoride and sulfate. These minerals need to be replenished and can be obtained both in food and supplemental form. Vitamin D3 is needed when taking calcium to ensure proper absorption, so speak with a physician before beginning a new calcium or bone supplement to make sure it won't counteract with other drugs or supplements you are taking. Proper nutrition and care, such as finding shoes that fit properly to ensure support of the skeletal system, are important factors for long-term bone health.
References
- "ACSM's Resources for the Personal Trainer"; American College of Sports Medicine; 2009
- "Principles of Anatomy and Physiology"; Tortora & Derrickson; 2009
- "Essentials of Strength and Conditioning"; Thomas R. Baechle and Roger W. Earle; 2000
