Skeletal System

Your bones perform a number of essential functions. They support and protect your internal organs. They act as levers and braces for your muscles to help you move. They also produce and store blood cells in the bone marrow. Although we may think of bones as being static, bones are actually living, growing tissue. Throughout a person's lifetime, old bone is removed (resorption) and new bone is added to the skeleton (formation). Normally, during childhood and the teenage years, new bone is added faster than old bone is removed.

According to the National Institutes of Health, three types of tissue can combine to make up mature bones:

• Compact tissue - This is the hard outer portion of most bones
• Cancellous tissue -This is the spongy tissue inside the bones that contains bone marrow, which makes blood cells
• Subchondral tissue - This is the smooth bone tissue of the joints

A layer of cartilage covers subchondral tissue to cushion the movement of joints.

It is never too early or too late to take care of your bones. There are many things we can do to keep our bones healthy and strong. Eating foods rich in calcium and vitamin D (Read about "Calcium" "Vitamins & Minerals"), getting plenty of exercise (Read about "Getting Started on Fitness"), and having good health habits help keep our bones healthy.

Good sources of calcium include low-fat dairy products, and foods and drinks with added calcium. Good sources of vitamin D include egg yolks, saltwater fish, liver and milk with vitamin D. Some people may need to take nutritional supplements in order to get enough calcium and vitamin D. Fruits and vegetables also contribute other nutrients that are important for bone health. (Read about "Dietary Guidelines")

But if we don't eat right and don't get enough of the right kinds of exercise, our bones can become weak and even break. Broken bones (Read about "Bone Fractures") can be painful and sometimes need surgery to heal. They can also cause long-lasting health problems.

Talk to your doctor about your bone health. Go over your risk factors with your doctor and ask if you should get a bone density test. (Read about "DEXA Scan - Dual Energy X-Ray Absorptiometry/Densitometry") If you need it, your doctor can order medicine to help prevent bone loss and reduce your chances of breaking a bone.

You can follow the links below to learn more about conditions and diseases of the bones.