Introduction to Bone Function
Osteoporosis is a metabolic condition associated with the skeletal system. The decrease in bone mass density and the demineralization of bones often results in bone fracture. The vertebral column, wrist and hip are the most commonly affected parts of the body.
The Role of the Skeletal System
The skeletal system has several important functions:
First, it provides the framework and shape of the body, allowing it to support weight-bearing activities and hold an upright posture.
Second, it supports the surrounding tissues such as the tendons, ligaments and muscles.
Third, it assists in movement through muscle attachments and the joints.
Other important functions include the protection of vital organs, the manufacturing of essential blood cells and the ability to store minerals such as calcium, magnesium and phosphorus.
Bones often undergo several changes over time. A normal phase of bone development is called bone remodeling. This occurs simultaneously with body growth starting in childhood and continues until young adulthood. Puberty is a period of rapid growth. During development and repair, the bones undergo a process of bone resorption and re-formation.
Bone resorption means the bone cells or osteoclasts break down bone which leads to the transfer of stored calcium in the bones to the blood. Bone resorption is vital to life because it is a part of the repair process. Old damaged tissue is replaced by new bone formation.
Bone Loss
Osteoporosis occurs when there is a significant decrease in calcium reserves for the body to utilize. This often occurs late in life but it does not necessarily mean that the disease will happen only in elderly people. The strength or the frailty of the bones depends on the calcium stored in the bones.
One method of measuring bone mass density is through dual energy x-ray absorptiometry (DEXA).
As a person ages, bone mass will gradually be lost. The bones become thinner as a person ages because bone resorption will outpace new bone formation. With this, the bones will lose calcium content as well as other minerals. This is why taking calcium and vitamin D is so important later in life.