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SPECIFIC BODY DEFENSES: The Lymphatic and Immune System. I. Lymphatic System. 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.
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I. Lymphatic System 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 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. Lymphatic System B. Composed of 3.Lymph Organs a.Lymph nodes • Areas of Concentrated lymphocytes and macrophages along the lymphatic vessels • Filter lymph
I. Lymphatic System B. Composed of 3.Lymph Organs b.Bone Marrow produces lymphocytes c. Spleen Serves as Blood reservoir Purifies blood and lymph
I. Lymphatic System B. Composed of 3.Lymph Organs c.Thymus causes pre-T cells to mature to T-cells d.Tonsils e.Peyer’s Patches
II. Immune Response A. Body’s 3 Lines of Defense 1.Skin 2.Mucous membranes 3.Immune system B.Immune System is 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 3.Humoral Immunity a. Provided by antibodies in the bodies 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 4.Cell Mediated Immunity a. Provided by nonantibody- producing 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
II. Immune Response • E. The Players • 1. B-Cells • work chiefly by secreting antibodies • Each B cell makes one specific antibody
II. Immune Response • E. The Players • 1. B-Cells • c. When a B cell encounters its triggering antigen it • gives rise to many large plasma cells that produce that specific antibody
II. Immune Response • E. The Players • 1. B-Cells • d. Antibody structure • 2 identical • heavy chains • and 2 identical light chains • shaped to form a Y.
II. Immune Response • E. The Players • 2. T-Cells • Function • Some help regulate the immune system • Others are cytotoxic (directly contact infected cells and destroy them
II. Immune Response • E. The Players • 2. T-Cells • b. Helper inducer T cells • activate B cells and other T cells • c. Suppressor T cells • turn off or suppress immune cells
II. Immune Response • E. The Players • 2. T-Cells • d. Cytotoxic T cells • rid the body of cells that have been infected by • viruses as well and cancer cells
II. Immune Response • E. The Players • 4. Killer Cells • a. cytotoxic T cells • recognize a specific antigen • b. Natural killer cells • donot require a specific antigen
II. Immune Response • E. The Players • 3. Cytokines • diverse and potent chemical messengers secreted by the cells of the immune system • Bind to specific receptors on target cells
II. Immune Response F. Immunity 1.Immunity • Whenever T cells and B cells are activated, some become "memory" cells • The next time that an individual encounters that same antigen, the immune system is primed to destroy it quickly
II. Immune Response F. Immunity 1.Active Immunity achieved by responses of ones immune system 2. Passive Immunity achieved with exogenous immune cells or products
II. Immune Response F. Immunity 3.Passive Immunity • achieved with exogenous immune cells or products • Long term • Can be stimulated by infection also by vaccines made from infectious agents that have been inactivated
II. Immune Response F. Immunity 3.Passive • short term • can be transferred passively from one individual to another via antibody-containing serum across the placenta
II. Immune Response F. Active, Passive and Acquired Immunity 3. Acquired Immunity comes from infection or from a new born’s mothe 4. Artificial Immunity comes from immunizations
II. Immune Response G. Autoimmune diseases 1. diseases caused by failure of the immune system to recognize “self 2.Examples a.rheumatoid arthritis (joints) b.lupus erythematosus (connective tissue) c.Graves’ disease (thyroid)
II. Immune Response G. 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
II. Immune Response G. 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