What causes us to be sick/what makes us sick? After we have become sick, how do we get better?

The Immune System

What is the immune system? Function: The immune system is your bodies defense system to protect you from disease and infection *Only job is to destroy anything that is not you Recognizes self vs. nonself

Self vs. nonself? Your immune system knows your what your protein receptors look like… Will destroy receptors it does not recognize!!!

2 types of defenses Lymphocytes T-cells B-cells Antibodies Skin (Nonspecific defenses) Skin Mucus (lysozyme) Inflammatory response Fever Phagocytes (Specific defenses) Lymphocytes T-cells B-cells Antibodies

1st line of defense (Innate Immunity) Nonspecific defenses: Physical barriers to keep stuff out SKIN Mucus 3rd

2nd line of defense Nonspecific defenses: Slow the pathogens down Inflammatory Response

2nd line of defense Nonspecific defenses: Slow the pathogens down Neutrophils and macrophages eat everything (lysozyme) Phagocytes

2nd line of defense Nonspecific defenses: Slow the pathogen down FEVER

Lymphocytes=white blood cells that search, destroy, remember 3rd line of defense Lymphocytes=white blood cells that search, destroy, remember T-Cells B-Cells Antibodies 1st Remembers the pathogens Helps turn on the immune system or kill infected cells

How are nonspecific defenses (innate immunity) different from specific defenses (acquired immunity)? The difference is that the nonspecific kills everything that is not you, specific only targets the ones they are assigned to.

Recognizing Pathogens Lymphocytes recognize pathogens by the antigens (receptor proteins) on their surface. If it is not you, its an antigen. Your immune system attacks

Antigens and Antibodies

How do antibodies work? Antigen is identified and cells make millions of antibodies that match the antigen Antibodies attach to the antigens like lock and key (very specific) which helps because: -Prevents bacteria and viruses from entering/ attacking your cells - Clumps them together for easy destruction ***- Flags the bacteria or virus for destruction

Turning on the Immune System

Activating the immune system Chicken Pox Virus

Activating the immune system Chicken Pox Virus

HIV and AIDs HIV= human immunodeficiency virus Reproduces in macrophages then starts infecting and destroying helper T cells No helper T-cells leads to a break down of the entire immune system. Normal person has 500-1000 helper t-cells in 1 drop of blood Less than 200 t-cells in 1 drop of blood = AIDS

Activating the immune system HIV Cold Virus