Fundamentals of Anatomy and Physiology

224 Chapter 9

Common Disease, Disorder, or Condition

Disorders of Muscle continued

cannot detach from the actin filaments. Therefore, the muscles remain in a state of

rigidity for about 24 hours. After 12 hours, the tissues degenerate and decay and the

rigidity is lost.

Snoring^
Snoring is caused by the rapid vibration of the uvula and soft palate producing a harsh,
rasping sound during sleep. This is caused by breathing through both the mouth and the
nose. Over-the-counter nasal dilators are on the market today to help alleviate this
problem.

Tetanus^
Tetanus is caused by the bacterium Clostridium tetani. The bacterium is anaerobic,
living in the absence of oxygen. Thus, stepping on an old nail, producing a deep
puncture wound, will transfer the bacterium to tissues with very little oxygen. This can
also occur with any deep cut or wound. The bacterium is very common in our
environment. When in tissues, it releases a strong toxin that suppresses the activ-ity of
motor neurons. The motor neurons produce a sustained contraction of skel-etal
muscles. Because it affects the muscles of the mouth, the disease is also called
lockjaw, causing difficulty in swallowing. Other symptoms include headache, muscle
spasms, and muscle stiffness. In the United States, we have an immunization pro-gram
to control tetanus. After the initial tetanus vaccine, booster shots are recom-mended
every 10 years to prevent the disease.

Polio^
Polio is caused by a virus that is an Enterovirus. It enters the spinal cord of the cen-tral
nervous system and affects the peripheral nerves and muscles that they control. The
virus attacks the motor neurons in the anterior horn of the spinal cord, which is gray
matter (polio in Greek means gray matter). In the 1940s and 1950s, thousands of
children in the United States contracted the disease called acute paralysis polio-
myelitis. Many developed paralysis of their limbs, had to wear braces, and some had to
be placed in “iron lungs” because they could not breathe properly. Fortunately, a
vaccine was developed (Salk and Sabin vaccines) and the disease is now quite rare in
the United States. However, it does occur in many third world countries where vac-cines
are not made available to people in spite of the Third World Health Organiza-tion’s effort
to eradicate the disease.

Plantar Fasciitis^
Plantar fasciitis is an inflammation of the connective tissue (fascia) that is part of the
arches of the foot. It can be very painful and is caused by continuous stretching of the
muscles and ligaments of the foot. Usually long-distance runners or individuals whose
occupations require lots of walking can develop this condition.

Fibromyalgia^
Fibromyalgia is a form of rheumatism but does not affect the joints. It is character-ized
by long-term tendon and muscle pain accompanied by stiffness, occasional muscle
spasms, and fatigue. There is no cure. It also causes sleep disturbance. It is also known
as fibrositis. It can produce pain in the shoulder and neck, arms, hands, lower back,
hips, legs, knees, and feet. Muscles relaxants, anti-inflammatory drugs, and physical
therapy are methods of treatment for temporary relief.