Common Skeletal System Disorders However, the two most common disorders of the skeletal system are osteoporosis and osteoarthritis. At least ten million people in the United States have osteoporosis, and more than 8 million of them are women.

Skeletal muscle is composed of long, fiber-like cells, which fuse together as they’re made. This means that each muscle cell has more than one nucleus because it is really made of several combined cells.

Skeletal muscle is heavily striated and multi-nucleated. These muscles are generally associated with bones and cartilages.

The nucleus contains the genetic material of the muscle cell. The sarcolemma is the name given to the plasma membrane of the muscle cell. There are specialized invaginations of the sarcolemma that run transversely across the cell. These invaginations are known as T tubules (short for transverse tubules).

With an average diameter of 10 μm, nuclei are normally found at the periphery of the myofiber, just below the plasma membrane. Nuclear positioning at the periphery of myofibers is a hallmark of skeletal muscle although the function of this structural characteristic remains elusive.

Size: Maximus (largest), minimus (smallest), longus (longest), and brevis (shortest) are common suffixes added to muscle names.

The 9 types of muscular dystrophy are Becker, congenital, Duchenne, distal, Emery-Dreifuss, facioscapulohumeral, Limb-Girdle, myotonic, and oculopharyngeal.

Fukuyama type congenital muscular dystrophy (FCMD) is one of several forms of a rare type of muscular dystrophy known as congenital muscular dystrophy. It is inherited as an autosomal recessive trait. Symptoms of this disorder are apparent at birth and progress slowly.

In its most common form, Limb-girdle muscular dystrophy causes progressive weakness that begins in the hips and moves to the shoulders, arms, and legs. Within 20 years, walking becomes difficult or impossible.