Name of the system: Immune System Immunity Name of the system: Immune System

What is Immunity? Immunity: ability to resist certain pathogens Pathogen- an “agent of disease.” It is the disease causer EX of pathogen: HIV, Flu, or common cold

How do we get Pathogens? Pathogens are transmitted by: Airborne (i.e. Influenza) Contaminated drinking water Vector- an organism that carries a disease (i.e. tick) Fluids (ex: HIV)

Does anyone know what cells fight infections?

White blood cells fight infections They are also called lymphoctyes

Kinds of Lymphocytes B-Cells T- Cells 1. Helper T 1. Antibodies 2. Cytotoxic T 3. Memory T 1. Antibodies 2. Memory B

Remember previous pathogens help produce specific antibodies T- Cells Helper T Assist Antibodies Cytotoxic T Killer T’s “Cell Police” Memory T Remember previous pathogens help produce specific antibodies

Specific Defense Pathogen have antigens on them Antigens- trigger the immune response Antigens have a protein, carbohydrate, or lipid on their surface

An Antigen These are proteins, They are often called carbs, or lipids on the surface They are often called surface “proteins”

ANTIBODIES Shaped like a Y Shape is Y so the antigen has 2 places to bind EX: Virus attaches to antigens, clumps them, & attracts WBC’s

Antibody Shape ANTIGEN BINDED

Steps to an Infection 1) Pathogen Invades 2) Antigens are recognized by a body’s B’cells 3) B cell’s produce specific antibodies and are released into the blood 4) Memory B & T cells are made to remember

Vocabulary Immunity Memory T Cell Pathogen Cytotoxic T cell Vector Lymphocyte Antibody Antigen Helper T cell

STOP

Homeostasis Disrupted Homeostasis is disrupted in 4 MAJOR ways: 1)HIV/AIDS 2) Organ Transplant 3) Cancer 4) Allergies

HIV/AIDS HIV= Human Immunodeficiency Virus AIDS = Auto Immune Deficiency Syndrome HIV is the virus you are infected with.

HIV attaches to T-Helper cells, and decreases immunity This is why people with HIV/AIDS are susceptible to many different kinds of infections

Cancer Not always recognized as foreign, because cancer is made by your own cells Cytotoxic T-cells are constantly surveilling for cancer Causes of cancer: viral, genetic, or chemical (radiation)

Allergies Antigens from allergens (i.e. pet dander) bind to Mast cells Mast cells release Histamine Mast cells are another type of immune cells, common in nasal passages Histamine is what causes the actual reaction *ADD allergens are harmless is general, but their antigen is recognized as foreign

Organ Transplant Cytotoxic T-cells ATTACK the new organ The new organ is seen as foreign Patients are put on immunosuppresants for life

STOP

2 kinds of Immunity Active Immunity Passive Immunity Natural (Maternal) Natural Acquired Acquired

Active Immunity: the body makes its OWN antibodies in response to an antigen Active Natural: an antigen enters your body and YOU make antibodies to fight it Active Acquired: A Vaccine EX: Chicken Pox

Vaccine A vaccine is weakened or mild form of a pathogen This weakened form stimulates an immune response to produce specific antibodies to this particular pathogen

Passive Immunity: lasts a LIMITED amount of time Acquired Passive: You are INJECTED with antibodies EX: Rabies Shots/anti-venom Natural Passive: When a mother breastfeeds her child she gives the child antibodies EX: breast milk

STOP

HIV Immune Video