SPECIFIC BODY DEFENSES The Lymphatic and Immune System

SPECIFIC BODY DEFENSES: The Lymphatic and Immune System

I. Basics A. Functions 1. Absorption and return of excess fluid the blood stream 2. Absorption of fat (in the villi of the small intestine) 3. Immune System Function

I. Lymphatic System Basics B. Composed of 1. Lymph – interstitial fluid 2. Lymph vessels a. Closely associated with circulatory system b. Similar to veins c. Contraction of skeletal mscl causes movement of lymph fluid through valves

I. Basics B. Composed of 3. Lymph Organs a. Lymph nodes » Areas of Concentrated lymphocytes and macrophages along the lymphatic vessels » Filter lymph

I. Basics B. Composed of 3. Lymph Organs b. Bone Marrow produces lymphocytes c. Spleen Serves as Blood reservoir Purifies blood and lymph

I. Basics B. Composed of 3. Lymph Organs c. Thymus causes pre-T cells to mature to T-cells d. Tonsils e. Pyer’s Patches

II. Immune Response A. Basics 1. The body's 3 rd line of defense 2. Amplifies inflammatory response B. Important Aspects 1. Antigen specific 2. Systemic 3. Has memory

II. Immune Response C. Kinds of Immune Response 1. Specific Immunity a. Antibodies bind only to antigen b. B-lymphocytes – antibody prod. c. T-lymphocytes – produce lymphokines 2. Nonspecific Defense a. Physical barriers b. Tears c. Phagocytes d. Fever / Inflammation

D. Kinds of Immune Response 1. Humoral Immunity a. Provided by antibodies in the bodies humors (fluids) b. Antibodies 1) Are produced by lymphocytes 2) Circulate freely in the blood and lymph 3) Bind primarily to bacteria, toxins, free viruses inactivates & marks for destruction

D. Kinds of Immune Response 2. Cell Mediated Immunity a. Provided by nonantibodyproducing lymphocytes b. Directly attack and lyse body cells. 1) containing viruses or parasite 2) Cancer cells 3) Foreign grafts c. Release chemical mediators 1) enhances inflammatory resp. 2) Help activate lymphocytes or macrophages

III. Cells of the Immune Sys. B. Natural Killer Cells 1. Similar to the killer T cell 2. Function as effector cells that directly kill certain tumors and viral-infected cells 3. kill their targets without a prior "conference" in the lymphoid organs. 4. More efficient if 1 st activated by T-cells

III. Cells of the Immune Sys. C. B Cells 1. production of antibodies 2. Antibody production and binding to a foreign substance or antigen, often is critical as a means of signaling other cells to engulf, kill or remove that substance from the body

III. Cells of the Immune Sys. D. Granulocytes or Polymorphonuclear (PMN) Leukocytes 1. neutrophils 2. Important in the removal of bacteria and parasites

III. Cells of the Immune Sys. E. Macrophages and Dendritic Cells 1. regulate immune responses 2. antigen-presenting cells (APC) 3. Functions Phagocytes Secretion of cytokines Antigen presentation

III. Cells of the Immune Sys. F. Dendritic Cells 1. antigen-presenting cells 2. More efficient APC than macrophages 3. capture antigen or bring it to the lymphoid organs where an 4. bind high amount of HIV, and may be a reservoir of virus

III. OTHER A. Active, Passive and Acquired Immunity 1. Active Immunity achieved by responses of ones immune system 2. Passive Immunity achieved with exogenous immune cells or products

III. OTHER A. Active, Passive and Acquired Immunity 3. Acquired Immunity comes from infection or from a new born’s mothe 4. Artificial Immunity comes from immunizations

III. OTHER C. Autoimmune diseases 1. diseases caused by failure of the immune system to recognize “self 2. Examples a. b. c. rheumatoid arthritis (joints) lupus erythematosus (connective tissue) Graves’ disease (thyroid)

III. OTHER D. AIDS - Immunodeficiency Syndrome 1. Causes death 2. Caused by Human Immunodeficiency Virus (HIV) 3. kills T-4 lymphocytes 4. T-4 lymphocytes induce B-lymphocytes to fight infection 5. Debilitated immune system

III. OTHER D. AIDS - Immunodeficiency Syndrome 6. no cure for HIV 7. HIV infection causes AIDS, and AIDS allows other infections to kill the person with the HIV infection

D. Kinds of Immune Response 2. Cell Mediated Immunity a. Provided by nonantibodyproducing lymphocytes b. Directly attack and lyse body cells. 1) containing viruses or parasite 2) Cancer cells 3) Foreign grafts c. Release chemical mediators 1) enhances inflammatory resp. 2) Help activate lymphocytes or macrophages