1. Lesson 2: Diseases and Disorders
Muscular System
Lesson 2: Diseases and Disorders

2. Lesson 2– Loss of Muscle Tone
Loss of muscle tone can result from serious illness.
Lack of muscle use can result in:
Atrophy
Contracture
Loss of Muscle Tone
Loss of muscle tone can result from serious illness, such as paralysis. Lack of muscle use can result in atrophy or contracture.
Atrophy is a reduction in size and strength of the muscle.
Contracture is a severe tightening of muscle resulting in permanent bending of a joint.

3. Lesson 2– Diseases and Disorders of the Muscular System
Muscle Strain
Fibromaylgia
Muscular Dystrophy
Diseases and Disorders of the Muscular System
Muscle strain is torn or stretched muscles or tendons.
It is caused by muscles being used too suddenly or for too long.
Symptoms include pain and swelling from bleeding inside the muscle.
Treatment involves rest, elevation, muscle relaxants or pain medications, and alternating hot and cold applications.
Fibromaylgia refers to a group of muscle disorders with chronic pain in specific muscle sites.
The exact cause is not known, but it is affected by stress, the weather, and poor physical fitness.
Besides pain, symptoms include fatigue, headache, and feelings of numbness and tingling. There is no inflammation.
Treatment involves rest, reducing stress, exercise, massage, and medication to relax muscles and relieve pain.
Muscular dystrophy refers to a group of inherited diseases in which the muscles gradually atrophy, or waste away.
Symptoms include painless, progressive muscle weakness. Severe forms cause total disability and eventually death; others cause a mild disability.
No cure is known. Treatment to slow the progress of the disease involves medication, physical therapy, and corrective surgery.