NOTES IMMUNE SYSTEM SPECIFIC DEFENSES Specific Defenses immune

NOTES – IMMUNE SYSTEM – SPECIFIC DEFENSES • Specific Defenses • immune system attacks a specific disease causing agent • ANTIGENS • something that triggers an immune response

• KEY CELLS • Lymphocyte • a type of wbc (white blood cell)

• B - lymphocyte • produces ANTIBODIES – attach to antigen to destroy bacteria • Antibodies • basic unit of the immune system • shaped like the letter “Y”

Specific Immune Response I. Cell Mediated Immunity • T – cells that directly attack antigens • KILLER T – CELLS cause pathogens to rupture & die • responsible for transplant rejection, destroying certain cancer cells, fungal infections

II. Humoral Immunity • PLASMA CELLS (specialized b – cells) release antibodies into the bloodstream when a pathogen enters the body • this process is aided by T – lymphocytes (T – cells) – wbc’s from thymus gland • T – cells help regulate production of antibodies by b – cells • Antibody Production • b – lymphocytes produce one cell that can rearrange its genetic code • this allows for many different types of antibodies

• can bind to two antigens at once – causes virus to AGGLUTINATE or clump together • phagocyte can then destroy the agglutinated virus • antibodies will do the same thing to bacteria

• Immunity • after exposure to certain diseases, the body does not become infected with those diseases again • EX: chicken pox • b – cells & T – cells remain capable of producing the same antibodies for life • this is called the SECONDARY IMMUNE RESPONSE • very quick – disease never gets a chance to develop

I. Active Immunity • injection of an ATTENUATED or weakened form of a virus or bacteria • Ex: Jenner & smallpox • allows body to produce immunity without contracting the disease first

II. Passive Immunity -- antibodies from another person or artificially produced introduced to protect another person Ex. Mother’s antibodies passed on to newborn

NOTES – IMMUNE SYSTEM DISORDERS • Allergies • results from an “overreaction” of the immune system • immune system produces chemicals called HISTAMINES – cause sneezing, runny nose, etc. • EX: food allergies, bee stings, penicillin, etc • can produce serious allergic reactions • Anaphylactic Shock • massive release of histamine – bronchioles contract – no air into or out of lungs

• Autoimmune Diseases • occurs when immune system attacks body’s own cells • can be the result of infection – Ex: Rheumatic Fever attacks heart as a result of strep throat • other ex: rheumatoid arthritis, juvenile diabetes, multiple sclerosis

• AIDS • What does AIDS stand for? • Acquired Immune Deficiency Syndrome • HIV • Human Immunodeficiency Virus – causes AIDS • retrovirus – genetic info is contained in RNA • begins in Helper T – cells, virus not affected by the immune system • virus makes it impossible for body to respond to disease • virus continually mutates – makes vaccine, medication difficult