Stress and the Immune Response Human Physiology November 8, 2001 Presented by Stacy Coester

How does stress affect the immune response? 3 aspects: What is stress? How does the immune system function? What are the effects of stress on the immune system?

Stress Physical sciences: A force exerted on a system that distorts or alters the structure of that system. Biological and human sciences: A force that exerts a distorting force on a person’s equilibrium.

Types of Stress Physical or psychological stressors: Physical: excessive heat or cold, tissue trauma, prolonged heavy exercise. Psychological: death of a spouse, divorce, personal injury or illness. Acute or chronic stressors: Acute: unpleasant films, prestige or status loss. Chronic: Sleep deprivation, social isolation. Distress or eustress: Distress: negative or destructive forms. Eustress: happy or good events that evoke a stress response.

Body’s Responses to Stress Gastrointestinal disease Increased risk of MI Delayed menarche and puberty Increased infertility Insomnia High blood pressure Impaired wound healing IMPAIRMENT OF THE IMMUNE SYSTEM!

Immune System Protects the body from invading disease organisms and other foreign bodies that do not belong in the body known as antigens or pathogens.

Cells of the Immune System

Lines of Defense Physical barriers Skin, linings of the gastrointestinal, genitourinary, and respiratory tracts. Cell-mediated immune response Phagocytosis and local inflammation Humoral immune response A specific response that occurs in 4 steps.

Stress and the Immune System Immune system is affected by and affects many other systems of the body. Cytokines orchestrate the immune response. Psychoneuroimmunology Interdisciplinary field that studies the relationship between psychology, neurology, and immunology. Stress doesn’t cause the disease–it sets the stage for illness.

Neuroendocrine Pathways

Influence of the Sympathetic Nervous System Hormone secretion increased in response to stress: Adrenaline, vasopressin, epinephrine, growth hormone, and prolactin Adrenaline is released from the adrenal glands Increased epinephrine levels cause lymphocyte migration to the skin from the bone marrow

Other Research Findings Psychological stressors cause increased cytotoxic T cell division which suppresses immune function. Increased infection might be caused in part because the physical barriers are compromised enabling more antigens to enter the body. Acute stressors appear to reduce the natural killer cell activity and lymphocyte responsivity. Chronic stressors at first cause similar results, but then actually enhance lymphocyte proliferation and cytotoxicity.

Stress: The Disease of the 21 st Century Thank you! Are there any questions or comments?