The different types of bones provide unique functions. Flat bones such as the skull, ribs and sternum protect vital organs. Long bones--the arms and legs--are the framework of the body. Bones store calcium and make new blood cells. The various types of muscles--smooth, cardiac and skeletal--support the body, pump blood and protect the internal organs. Diseases affect muscles and bones throughout the body.
Osteosarcoma
Osteosarcoma, the most common type of bone cancer, occurs most often in children and teenagers, the American Cancer Society says. Though osteosarcoma can develop in any bone, the most common location is in the bones around the knee. Osteosarcomas are further divided into three types: high-grade osteosarcomas, which include osteoblastic, mixed, small cell chondroblastic, fibroblastic, telangiectatic and juxtacortical high grade; intermediate-grade osteosarcomas, which include periosteal; and low-grade osteosarcomas, which include parosteal and intramedullary. Treatment and prognosis depends on the grade and stage of the tumor.
Myasthenia Gravis
Myasthenia gravis, a chronic autoimmune disease of the neuromuscular system, causes weakness in the skeletal muscles. Affected muscles include those responsible for eyelid movement and facial involvement, such as chewing, swallowing and talking. Poor muscle control occurs when there is a loss of adequate communication between the muscle and the nerve. Antibodies produced by the body's immune system attack the acetylcholine receptors that initiate muscle contraction. Symptoms of myasthenia gravis are most common in women younger than 40 and in men older than 60, reports the National Institute of Neurological Disorders and Stroke. Treatment of myasthenia gravis consists of controlling the symptoms through medications and therapies.
Myotonic Muscular Dystrophy
Myotonic muscular dystrophy, or MMD, is a type of muscular dystrophy that usually doesn't present until adulthood. MMD causes difficulty in muscle relaxation, which is a symptom unique to the myotonic type of muscular dystrophy. Congenital MMD symptoms are different from the adult-onset and include weakness in the muscles controlling breathing and swallowing. In adult-onset MMD, symptoms usually start with weakness of the muscles farthest from the body and progress toward the body to include the head, neck and face muscles. According to MDA Publications, treatment goals for both types of MMD--Type 1 from chromosome 19 and Type 2 from chromosome 3 abnormalities--are symptom management.
Mastoiditis
The most common cause of mastoiditis, an infection of the mastoid bone in the middle ear, is acute otitis media, reports MedlinePlus. Mastoiditis affects children more often than adults, and it presents with fever, ear pain, ear drainage and headache. In some cases, hearing loss or swelling behind the ear may occur. Treatment requires antibiotics, and in severe cases, surgery to drain the mastoid bone.
