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William E. Prentice


When you finish this chapter you should be able to

  • Analyze the role of the immune system in preventing disease.

  • Differentiate different viral infections that may affect the patient.

  • Identify symptoms and signs of respiratory infections.

  • Categorize disorders of the muscular system.

  • Examine disorders associated with the nervous system.

  • Recognize disorders of the vascular and lymphatic systems.

  • Explain diabetes mellitus, and contrast diabetic coma and insulin shock.

  • Indicate the causes of epilepsy and explain how to perform the appropriate action when a seizure occurs.

  • Explain what causes hypertension and how it may be controlled.

  • Describe the classic symptoms and signs of cancer.

  • Compare and contrast the symptoms and signs of the most common sexually transmitted diseases.

  • Explain menstrual irregularities and their effect.

  • Review female reproduction and pregnancy.


In addition to the many injuries that have been discussed in previous chapters, a variety of additional medical conditions can affect a patient. When illnesses occur, it is the athletic trainer's responsibility to recognize these conditions and to follow up with appropriate care. Appropriate care for the illnesses and conditions discussed in this chapter often means referring the patient to a physician to provide medical care that is beyond the scope of the athletic trainer. The information provided in this chapter serves as a reference for the athletic trainer in making appropriate decisions regarding care of the sick patient.


The immune system is not an organ system but is instead a collection of disease-fighting cells populating the lymphatic and other organ systems that recognize the presence of foreign substances in the body and act to neutralize or destroy them.96 (See Chapter 14) Illness results when the immune system fails to neutralize or destroy the invading offender. Immunity means being protected from a disease by having been previously exposed to an invading agent, called an antigen. When an antigen invades the body that is not recognized by the immune system an adaptive immune response occurs. Adapted immunity can be achieved naturally as the immune system mounts a specific response to the antigen, or immunity can be acquired through vaccines.48

A natural immune response disposes of the antigen and thus prevents damage. The immune response may be cell-mediated, in which lymphocytes (T cells) are produced by the thymus in response to the antigen exposure. There may also be a humoral immune response, in which plasma lymphocytes (B cells) are produced, with the subsequent formation of antibodies. An innate, or nonspecific, immune response—inflammation—is the reaction of the tissues to injury from trauma, chemicals, or ischemia that always occurs, regardless of the cause. These are all positive responses that collectively destroy or neutralize an antigen.57

However, an autoimmune response directed against ...

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