Tuesday, January 13, 2009

Bones and Muscles

Giving The Body Structure and Movement
By Courtney Hammond

The structural system does exactly what its name implies; it provides structure or a framework for the body. It gives the body its form and the ability to move. The structural system is comprised of bones, connective tissue and muscles.

A newborn baby has about 300 soft bones—some bones are actually cartilage at this stage of development. As the baby grows, the cartilage calcifies as calcium phosphate permeates the bones. Eventually the calcified cartilage is replaced by true bone, and some of the baby’s bones fuse together. An adult has between 206 and 209 bones, depending on the number of ribs and an extra bone in the tailbone.

Bones stop growing in size during the mid-teens for girls and around age 20 for boys, though the growing process lasts as bones constantly rebuild themselves. Bones contain two types of cells—osteoblasts and osteoclasts—which work together to build new bone material on the outside and remove old material on the inside. To sustain this regenerative effort, the body must receive sufficient supplies of vitamin D, calcium and phosphorus. If a shortage of these minerals occurs in the bloodstream, the body will pull them from the bones, which can lead to weak and porous bones.

Connective Tissue

Some of the most important connective tissues in the structural system are those that make up the joints. Joints are designed to permit movement between bones that must meet, but not touch. These engineering marvels bind two or more bones together while cushioning and lubricating them to withstand a lifetime of bending, twisting, swinging and lifting.

The body has many different types of joints. Some allow for a wide range of movement, such as the hinge joints of the elbow and knee, or the ball and socket joints of the hip and shoulder. Other joints allow for more limited movement, such as those found in the spine. Most joints are composed of similar elements. The joint is enclosed in a tough fibrous capsule filled with synovial fluid to lubricate the moving parts of the joint. Ligaments surround the capsule to protect it and provide stability to the joint.

Cartilage is a type of dense connective tissue. It is made up of chondrocytes that produce a matrix of collagen and elastin fibers. Cartilage provides support and structure to body tissues without being as rigid as bone. It also serves to cushion the joints.

Bones and joints provide the framework for the body and determine how it can move. Muscles create the movement by converting chemical energy from food into physical energy. There are more than 600 muscles in the body in three basic types: cardiac muscle, smooth muscle and skeletal muscle. Each muscle is made up of countless fibers, and each fiber is composed of minute filaments that vary in length.

Muscles produce movement by contracting. They never push; they pull, which means a pair of muscles is required to make a full range of movement. Muscles grow through use. The effort it takes to use muscles signals the heart to supply them with more blood and nutrients, which in turn stimulates the growth of the size of each muscle fiber.

When Things Go Wrong
Damage to the structural system can affect the way you move and enjoy life. Three of the most common problems occurring in the structural system are osteoporosis, osteoarthritis and fibromyalgia.

Osteoporosis is characterized by low bone mass and a loss of bone tissue, leading to weak and brittle bones that are prone to breaks. Osteoporosis is especially common among post-menopausal women, but men also develop osteoporosis. While it is usually thought of as a disease for the elderly, research shows that peak bone density is achieved by age 25. It is vital that men and women alike develop strong bones by that age so the bones can remain strong throughout life. While the best defense against osteoporosis is to build strong bones during childhood and adolescence, other steps can help you lower your risk, such as getting adequate amounts of calcium and vitamin D, engaging in regular weight-bearing exercise and choosing a healthy lifestyle free of smoking and excessive alcohol.

Arthritis is a general term for a group of conditions involving damage to the joints of the body. The most common form of arthritis is osteoarthritis, and this is the leading cause of chronic disability in the United States. Osteoarthritis is caused by an abnormal wearing of cartilage in the joints, a decrease in the synovial fluid surrounding the joints, and chronic low-grade inflammation. Since the bone surfaces in the joint are inadequately protected, osteoarthritis sufferers experience pain with weight-bearing activities, including walking and standing.

Fibromyalgia is characterized by chronic muscle pain. This disorder is not entirely understood and is often referred to as fibromyalgia syndrome because researchers are learning that pain is just one element of fibromyalgia. Associated pain can present itself in a variety of ways, from muscle pain, spasms and weakness, to sleep disturbances. Other sufferers also experience brain fog and depression. The cause of fibromyalgia is unknown, but certain triggers such as stress, physical exertion and lack of deep sleep seem to exacerbate symptoms.

A healthy structural system is built on basic principles of good nutrition, particularly adequate vitamin D and calcium intake, and regular exercise. The structural system gives your body strength and the ability to move. Taking care of it will allow you to engage in your favorite hobbies and activities for a lifetime.

Related Article: Structural System Support

No comments:

Share This Post