The Immune System https://www.youtube.com/watch?v=z3M0vU3Dv8E

The Immune System … in Action When a mosquito bites When you breathe When you have allergies When you get a blood transfusion When you die ....also called the Lymphatic System

I. Parts of system: A. The Lymphatic System contains lymph, which is a clear liquid that circulates through the lymph vessels Edema occurs if this fluid builds up in areas

Edema and Pitting edema

B. Lymphatic Organs i. Contain a large number of lymphocytes (white blood cells) ii. Red Bone Marrow, Thymus Gland, Lymph Nodes, Spleen, Tonsils

II. Defenses A. Nonspecific - barriers to entry (skin), inflammatory response, phagocytes, natural killer cells Skin: low pH, normal flora (bacteria) Inflammation: increase heat, swelling, macrophages eat antigen Antigen: bad guy or foreign substance

Defenses B. Specific - require B Lymphocytes and T lymphocytes (B cells and T cells) Antibodies: protein produced by body that recognize specific antigens (mark the antigen to slow it down and so macrophage find it to eat it)

Defenses 1. Types of white blood cells B Lymphocytes: humoral response (in the fluid)- produce antibodies and memory cells in fluid T Lymphocytes: cell-mediated response- produce killer T cells that kill infected body cells Helper T Cells - activate Killer T cells and B cells Activate the whole process: this is what HIV destroys

Typical Immune Response

2. Humoral vs cell-mediated B Lymphocytes, vs T Lymphocytes Fluid (blood, lymph in infected cells

3. Innate vs adaptive (acquired) General, immediate, vs specific, lag time, no memory memory Phagocytes B & T cells Cytokines are a broad and loose category of small proteins that are important in cell signaling. They are released by cells and affect the behavior of other cells, and sometimes the releasing cell itself.

3. Active vs passive immunity Built up in body vs borrowed/ shared Long term short term

C. Other Cell Roles Macrophages - consume pathogens, (also called phagocytes) Neutrophil - suicide bomber cells that destroy cells infected by a virus B Cells - mature into plasma cells when stimulated Plasma Cells – produce antibodies specific to an invader Cytotoxic (Killer) T Cells - bump into infected cells, poke holes in them and destroy them Helper T Cells - activate Killer T cells and B cells

Another Look Animation of the process from McGraw Hill

Still confused, check out Bozeman https://www.youtube.com/watch?v=z3M0vU3Dv8E

How Do Vaccines Work? Vaccines contained a killed or weakened part of a virus (or other pathogen) to stimulate your immune system to react to the antigen. Once you have antibodies for that microbe, the real one will not make you sick. Why do some people not want to vaccinate their children? Why do some people choose not to get the flu vaccine?

Why you shouldn’t trust drugs that say they boost your immune system.

Lupus, multiple sclerosis, allergies, arthritis psoriasis, Some people already have boosted immune systems….. they suffer from AUTOIMMUNE DISORDERS: abnormally low activity or over activity of the immune system Lupus, multiple sclerosis, allergies, arthritis psoriasis, onset of diabetes Lupus is a widespread and chronic autoimmune disease that, for unknown reasons, causes the immune system to attack the body’s own tissues and organs, including joints, kidneys, heart, lungs, brain, blood, and skin. - See more at:

Autoimmune disorders are often treated with steroids, which suppress the immune system.

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