The muscular system is an extensive network of muscle and nervous tissue which is spread throughout the body. It is controlled by the central nervous system, which sends out an assortment of signals to keep the body running smoothly. There are over 650 muscles active in the human body, and the muscular system can comprise up to 40% of someone's weight. This complex interconnected system is essential for human life; without it, people cannot move and perform an assortment of bodily processes which are essential to keep the body in working order.
There are three different kinds of muscle: voluntary, involuntary, and cardiac. Cardiac muscles, as you might imagine, are located in the heart, and they are a form of involuntary muscle. These muscles keep the heart beating, ensuring the blood is pumped through the body. They are controlled by the autonomic nervous system.
Involuntary muscles line the internal organs of the body, contracting and relaxing to push a variety of substances through the body. These muscles are also controlled by the autonomic nervous system, which sends an assortment of signals to keep them working smoothly. Involuntary muscles are also known as “smooth muscles,” and they control things like your stomach, digestive tract, reproductive tract, breathing, and so forth. When signals to these muscles are interrupted, it can be catastrophic.
Voluntary muscles are the muscles you use to do things like throwing balls, walking, lifting objects, and so forth. They are also called skeletal muscles, and they are controlled by signals from your brain which trigger them into a contraction, generating the desired movement. They often work in pairs to accomplish the desired goal. These muscles are vulnerable to stress, as you may be aware if you have ever “pulled” a muscle.
The amount of coordination and communication involved to keep the muscular system running is rather impressive. In addition to keeping the functions of the body in order, the muscular system also provides the support which allows your body to stand up, and it connects the skeletal system. Many people like to exercise to tone and strengthen the muscular system, expanding their range of motion and allowing themselves to perform a wide variety of tasks, from competing in triathlons to dancing.