There are over 600 muscles in the body that work together with tendons and ligaments to allow body movement. Skeletal muscle, also called voluntary muscle, is responsible for voluntary movement, such as lifting an arm. Smooth muscles line internal organs and aid in involuntary movement such as digestion. Cardiac muscle is located only in the heart and is responsible for allowing the heart to beat. Diseases of the muscular system cause improper functioning of many of these muscles.
Rhabdomyolysis
Muscles are made up of muscle fibers that are composed of a substance called myoglobin. Rhabdomyolysis is a condition characterized by the breakdown of muscle fibers, which causes myoglobin to be released into the bloodstream. When myoglobin enters the bloodstream, it travels to the kidneys, where it is broken down in substances that can be harmful to the kidneys. Rhabdomyolysis is most often caused by trauma to the skeletal muscle, according to Medline Plus. These substances can block kidney structures and ultimately lead to kidney failure.
Symptoms of rhabdomyolysis include abnormal urine color, weakness, muscle stiffness, muscle aching, fatigue, joint pain and seizures. Treatment for rhabdomyolysis consists of flushing out the bloodstream and kidneys with intravenous fluids. If the condition is very mild, diuretics may be sufficient enough to flush out the body. If kidney damage has occurred, dialysis may be necessary.
Duchenne Muscular Dystrophy
Duchenne muscular dystrophy is an inherited disease that is characterized by a rapid weakening of the muscles. The disease is caused by a defective gene in a muscle protein called dystrophin. Symptoms of Duchenne muscular dystrophy include fatigue, muscle weakness, problems with motor skills and difficulty walking. Symptoms usually begin before the age of 6 and by the age of 12, a wheelchair is necessary, according to the University of Maryland Medical Center. There is no cure for Duchenne muscular dystrophy, but treatment is aimed at improving quality of life. Physical therapy and physical activity can help to prolong motility.
Polymyositis
Polymyositis belongs to a group of muscle diseases called inflammatory myopathies, which are characterized by chronic muscle inflammation and accompanying muscle weakness. Polymyositis most often affects the proximal skeletal muscles, the muscles that are located the closest to the body core, according to the National Institute of Neurological Disorders and Stroke. In addition to muscle weakness, other symptoms of polymyositis include shortness of breath, difficulty swallowing, difficulty speaking and heart arrhythmias. Polymyositis cannot be cured, but a combination of physical therapy, heat therapy, medication and exercise can improve symptoms. Immunosuppressant drugs may also be given if other treatment options are not successful.
