Tuesday, May 17, 2011

Homeostatic Imbalances

Most important disorders of the immune system are autoimmune diseases, allergies, and immunodeficiencies.

Autoimmune diseases- the body produces antibodies and sensitized T cells that attach and damage its own tissues. A few examples include:
  • Multiple sclerosis- which destroy the the white matter of the brain and spinal cord
  • Graves' Disease- which the thyroid gland produces excessive amounts of thyroxine

Allergies- abnornally vigorous immune responses in which the immune system causes tissue damage as it fights off a perceived "threat" that would otherwise be harmless to the body. The most common allergy is:

  • Immediate Hypersensitivity- this is triggered by the release of a flood of histamine when IgE antibodies bind to mast cells. Histamine causes small blood vessels in the area to become dilated and leaky and is largely to blame for the best-recgnized symptoms of allergy: a runny nose, watery eyes, and itching.

Immunodeficencies- include both congenital and acquired conditions in which the production or function of immune cells or complement is abnormal.

  • Acquired Deficiency Syndrome- is currently the most important. This syndrome cripples the immune system by interfering with the activity of helper T cells.

No comments:

Post a Comment