Your body consists of over 600 muscles that make up about 40 percent of your total body weight. These muscles are constantly contracting and relaxing in an effort to make your body parts move. You can increase the strength of your muscles by exercising, and likewise, a sedentary lifestyle can make them weaker and smaller.
The Facts
The strongest muscle in your body is the heart, which is constantly beating at an average resting rate of 70 to 80 beats per minute. The type of muscle that allows your body to move is called skeletal muscle. Skeletal muscle is connected to your bones via flexible tendons, and you can increase the size and strength of these muscles by working out. Skeletal muscle can only pull, not push, so that's why they come in pairs.
Significance
Muscles play a significant role in your body's overall function. Certain muscle disorders can cause weakness, pain or in extreme cases paralysis. The National Institutes of Health points out the following serious muscle disorders: muscular dystrophy, some cancers and myositis. Injury, such as sprains or muscle strains, can cause damage to muscles as well. Muscle disorders can affect any type of muscle within your body, including skeletal muscle and involuntary muscles.
Types
There are three types of muscle in your body. Skeletal muscle is referred to as voluntary muscle because you control the movement. Smooth muscle, also called involuntary muscle, is found in your digestive system, blood vessels, airway and in the female uterus. You cannot control smooth muscles. Cardiac muscle is the final type, and it is your heart muscle.
Features
Skeletal muscles feature cells called fibers, and these fibers contain many myofibrils, which are cylinders of muscle proteins that allow the muscle to contract. This contraction is what causes your skeletal muscles to move. By increasing the number of muscle fibers in your body, you can increase the size and strength of your muscles.
Effects
Muscles are triggered by an electrical impulse generated from your nervous system. This causes the muscle to use energy in the form of ATP, Adenosine-5'-triphosphate. The muscle actually makes its own ATP in a three-step process that involves creatine phosphate, anaerobic respiration and aerobic respiration. This is the reason many bodybuilders and athletes choose to supplement creatine in their diet. Check with your doctor before trying a creatine supplement.
