More than 600 active muscles allow you to do everything from walk to turn your head to look in the rearview mirror. The simple work of the muscular system is to contract and relax based on signals from the brain.

Muscles are attached to the bones in your body to allow visible movement, but there are internal muscles that work to pump blood, release urine and a other highly necessary tasks.

Muscles allow you to smile or reach out and give someone an affirming hug. Involuntary muscles in the lungs allow you to breathe.

The TrueStarHealth.com website indicates, "Each muscle is made up of thousands of individual cells, also called muscle fibers. While the number of muscles cells/fibers can not increase, each individual muscle fiber has the potential to increase in size, density and efficiency." [1]

Every area of your body is affected by the ability of your muscles to contract and relax. The consistent use of those muscles can allow for long-term mobility.

Muscle Facts

•There are three types of muscle tissue 1) skeletal, 2) smooth and 3) cardiac. [2]
•A single muscle cell is called a muscle fiber. [2]
•Muscle tissues are excitable tissues – generation of an action potential causes contraction. [2]
•On average, probably 40% of your body weight is in muscles. [3]
•The cells of your muscles use chemical energy from the food you eat. [3]
•You have over 30 facial muscles, which create looks like surprise, happiness, sadness, and frowning. [3]
•Eye muscles are the busiest muscles in the body. Scientists estimate they may move more than 100,000 times a day! [3]

Schools develop age appropriate physical education programs in an effort to combat childhood obesity and to keep muscles conditioned for long-term use. The Presidents Council on Physical Fitness places a high priority on fitness. "Physical activity is vital to promote and maintain health, but it's easy for many of us to overlook," [Health and Human Services] Secretary [Mike] Leavitt said. "The physical activity guidelines will underscore the importance of physical activity to America's health and assist on the journey to a healthier life. Good health -- wellness -- doesn't just happen. Wellness has to be a habit." [4]

The contraction aspect of muscular tissue is not simply a function of voluntary muscles that control movement, but also the involuntary movement of inner muscular organs.

The importance of the body's muscular system is widely recognized and is dependent on the skeletal system as well as in supporting the life sustaining benefits of the heart, lungs and other internal systems. If the brain is the body's computer system, the muscular system is a partner in mobility.

Perhaps the muscular system
looks designed because it is designed.

[1] http://www.truestarhealth.com/members/cm_archives11ML3P1A20.html
[2] http://faculty.ccri.edu/pmoberg/muscle_facts.htm
[3] http://yucky.discovery.com/flash/body/pg000123.html
[4] http://www.hhs.gov/news/press/2006pres/20061026.html