Most of us take our muscles for granted, not realizing how crucial they are to us. Muscles are the body’s engine, and energy is the fuel. It would be impossible for us to do anything without them, including expressing ourselves. We convey ideas through spoken words using the muscles of the mouth, tongue and larynx, through written words using the muscles of the fingers, or through body language using skeletal muscles.
The human body contains more than 630 muscles. Approximately 35-45% of body mass is muscle tissue. Muscles are long- lasting, self-healing and grow stronger with use. There are three unique kinds of muscle:
• Cardiac muscle, which is found only in your heart. It contracts involuntarily; it is automatically controlled by the nervous system.
• Smooth muscle is found in blood vessels, the digestive system, bladder, airways, and the uterus in a female. It also contracts involuntarily.
• Skeletal muscle is the kind we can see and feel. They attach to the skeleton and come in pairs; one muscle to move in one direction and another to move back the other way. Skeletal muscles contract voluntarily, you have to think about contracting them and the nervous system tells them to respond.
The combination of muscles and bones make up the musculoskeletal system. Together, the skeletal muscles work with bones to give the body its power and strength.
In most cases, skeletal muscle is attached to one end of a bone, stretches across a joint, and then attaches again to another bone. Tendons serve as connector pieces between muscle and bone; when a muscle is contracted, the tendon and bone move along with it.
Skeletal muscles come in a variety of sizes and shapes depending on their job. The muscles in your back, near the spine, are some of the biggest and most powerful. These muscles have the difficult job of keeping the body upright and providing the power to lift and push.