The muscular system is a very important part of the human body. It has many components and functions and is the source of body movement. There are around 650 muscles in the human body and they are different types of muscles. Muscles can be voluntary or involuntary, which means controlled or uncontrolled movement. Muscles have many reasons and in this article you will expand your knowledge of muscles and their functions as well as their diseases and how they help maintain the body. There are three different types of muscles in the body, and the first ones we'll talk about are the skeletal muscles. The body is made up of approximately 640 skeletal muscles and they happen to be the only voluntary or (controlled) muscles. Their main function is to contract and expand so that the bones can move. Most skeletal muscles are attached to bones or joints so that the muscle can expand or contract to create movement. They are made up of band-like fibers attached and bunched together that run along the bone. These fibers are held together by connective tissue called epimysium, which also protects the muscle. Skeletal muscle is what makes the body able to walk and move, without these skeletal muscles the body could not function properly because it would have nothing to rely on for stabilization and strength. They contain the so-called striated cells, that is, cells that have the shape of bands and are individual, they stretch along the entire length of the muscle so that they can contract with it and these cells are also those that give energy to the muscle through the respiration of the muscle. proteins, fats and glucose which constitutes the energy supplement of all muscles. For example, refer to Figure 1-1, 1-4 and 1-5 for the cell. Another type of muscle is the smooth muscle or (vi...... center of paper ...... wound muscles, the largest appears to be skeletal muscle called gluteus maximus and the hardest working muscle is in the eye. Muscles are very vital to the human body and, as seen above, humanity could not survive without this system. It helps for energy, movement, temperature stabilization, pumps the blood and keeps everything functioning correctly as well as many other things. However, the muscles do not do everything by themselves, the muscles work with all the other systems of the body, especially with the nervous system because that is where they receive all the impulse signals from the brain so that the muscles are able to do the things they are capable of. Works Cited www.livescience.com cross-referenced with www.humambodyfacts.com, www.wiseGeek.org Alcamo, Edward and Krumhardt, Barbara Anatomy and Physiology The Easy Way, New York.: Barron's Educational Series, inc. 1996