What’s the difference between humans and jellyfish? Well, for one thing (out of many), it is our bony skeleton! There are 206 bones in the body. The human skeleton is a strong structure that is made up of bones, ligaments, cartilage and joints.
This week I will focus in on the bones of the skeletal system. The bones perform a variety of functions including protection, movement, the production of blood cells, and the storage of minerals necessary for good health.
The bones as protection
Amazingly, bones weigh very little considering their strength. The entire adult human skeleton weighs about 21 pounds, yet it can withstand impacts as if it were made of steel. In fact, the act of walking or running can put pressure on the bones of the feet in excess of 500 pounds in an average person.
Flat bones are great protectors of the internal organs. Protection is evident with ribs, the flat, curved bones that protect the contents of the chest including the heart, lungs, spleen, liver and other organs.
The bones of the spine are flexible, allowing us to stand, walk and run while protecting the sensitive spinal cord within. The flat bones of the skull protect the brain, and the flat bones of the pelvis protect reproductive organs in women and the bladder in all people.
More than protection
Bones are actually considered living organs. Inside, they contain bone marrow that produces both red and white blood cells. Marrow is a powerhouse factory of blood production, producing more than 90 billion blood cells daily.
Bones themselves are constantly being remodeled, both broken down and rebuilt. The breakdown releases calcium and phosphorous into the blood stream, which makes these minerals available for new bone construction and other vital functions.
In contrast to the flat, protective bones, there are other long bones like those found in the arms and legs and hands and feet that are extremely strong, allowing weight-bearing movement. Long bones are made of two different parts: compact and spongy.
Spongy bone forms the inside part of long bones where the marrow resides to produce blood cells. The outer part of long bones is called “compact” bone, giving strength to the skeleton needed for movement and action activities. Movement occurs via the bones’ attachment to muscles and joints.
The thighbone (femur) is the longest bone in the human body, averaging 19 inches in length in adults. There are other short, strong “cube-shaped” bones like those found in the wrists and ankles that are intimately involved in finer movement, too.
Keeping healthy by building strong bones
After about age 32, a human body loses more bone than it makes. Over time, this loss can have deleterious health effects.
Starting at about age 30, the body loses bone more quickly than it makes bones. Bone thinning is called osteopenia. Bone thinning to the point where it is considered a disease is called osteoporosis.
There are good treatments for osteoporosis. But, to prevent osteoporosis and to maintain good bone health, here are a few recommendations:
- Make sure your diet includes plenty of calcium. Calcium builds strong bones.
- Make sure your diet includes vitamin D, essential for good bone health.
- Engage in weight-bearing activities such as walking, running, or any other vigorous exercise like basketball, tennis or soccer.
- Avoid cigarette use. Smoking has been demonstrated to be deleterious to good bone health.
Be sure to have regular checkups, and you can discuss with your doctor the best way to maintain healthy levels of vitamin D and calcium. Take good care of your bones and they will take great care of you.
Charles E. Crutchfield III, MD is a board certified dermatologist and Clinical Professor of Dermatology at the University of Minnesota Medical School. He also has a private practice in Eagan, MN. He has been selected as one of the top 10 dermatologists in the U.S. by Black Enterprise magazine and one of the top 21 African American physicians in the U.S. by the Atlanta Post. Dr. Crutchfield is an active member of the Minnesota Association of Black Physicians, MABP.org.
Charles E. Crutchfield III, MD is a board-certified dermatologist and clinical professor of dermatology at the University of Minnesota Medical School and a Benedict Distinguished Visiting Professor of biology at Carleton College. He also has a private practice, Crutchfield Dermatology in Eagan, MN.
He received his MD and Master’s Degree in molecular biology and
genomics from the Mayo Clinic. He has been selected as one of the top 10 dermatologists in the United States by Black Enterprise magazine. Minnesota Medicine recognized Dr. Crutchfield as one of the 100 Most Influential Healthcare Leaders in Minnesota. Dr. Crutchfield specializes in
skin-of-color and has been selected by physicians and nurses as one of the leading dermatologists in Minnesota for the past 18 years.
He is the team dermatologist for the Minnesota Twins, Vikings, Timberwolves, Wild and Lynx. Dr. Crutchfield is an active member of both the American and National Medical Associations and president of the Minnesota Association of Black Physicians. He can be reached at CrutchfieldDermatology.com or by calling 651-209-3600.