THE IMMUNE SYSTEM How Do We Keep Our Bodies Healthy? Name: Date: Block: Assign#:

What causes certain diseases? PATHOGENS = specific microorganisms that cause diseases by attacking healthy cells Ex/ bacteria, virus, fungus, parasites Source: biojobblog.com

IMMUNE SYSTEM = the body system that fights off illness and disease Contains general defenses against pathogens (any germs or chemicals that can make you sick) Source: Does-Our-Immune-System-Work-2.jpg/

SURFACE BARRIERS 1st line of defense Shield to keep pathogens out EX/ Skin, mucous, tears, saliva, and stomach acids Source: visualphotos.com

GENERAL IMMUNE RESPONSE 2nd line of defense for pathogens that get by the surface barriers General germ fighters that starts attacking if pathogens get into the body

WHITE BLOOD CELLS aka Leukocytes Patrol your bloodstream, looking for invaders Recognizes and destroys invaders Housed in the LYMPH NODE - clumps of tissue where white blood cells mature and stay! If a germ isn’t recognized, it can multiply and make you sick Source: healthinfoispower. wordpress.com Source: cpnonline.org

MACROPHAGE (1 of 6 Types of White Blood Cells) Engulfs identifying markers (antigens) from the invading bacteria and present them on its own surface Source: medimagery.com

INFLAMMATION Blood vessels widen to bring more blood to the site (i.e. WHITE BLOOD CELLS!) Sometimes inflammation results in FEVER! The high temperatures make it harder for pathogens to survive! versus

NATURAL KILLER CELLS Find cells that are INFECTED with the pathogen and kills them Poke holes in the infected cell and release chemicals that flow IN to kill the infected cell (“apoptosis”) Source: nida.nih.gov

ADAPTIVE IMMUNE RESPONSE Specific defenses that: 1.Attacks the pathogen in the body 2. Remembers the pathogen to protect the body in future attacks!

ANTIGEN A protein marker on a cell’s surface that helps the immune system identify a foreign substance Source: m.medlineplus.gov

ANTIBODY = a protein that recognizes and binds with a SPECIFIC antigen found on the invading germ When white blood cells figure out what makes you sick, they create antibodies to fight the infection Like a “red flag”- signals leukocytes to kill the germ Source: biotoxins/detection/images/AntibodyMolecule.jpg

Lymphocytes: (1 of 6 Types of White Blood Cells) B cells: Notice antigens presented on the macrophage and produce ANTIBODIES which inactivate pathogens (that haven’t yet infected a body cell) Helper T cells Killer T cells: destroy body cells that are infected with pathogens Source: smabiology.blogspot.com Source: medimagery.com

DENDRITIC CELL 1. Captures an invader 2. Presents pieces of the invader on its surface 3. Travels to the lymphn node to activate T cells and B cells by presenting them with pieces of the invader 4. Depending on the invader, an immune response involving antibodies or killer cells results

YOUR IMMUNE SYSTEM REMEMBERS! When you have the chicken pox, your body remembers the antibodies it built to fight it off If the chicken pox pathogen tries to enter your body again, your immune system will know how to get rid of it Source: smabiology.blogspot.com

WHAT WEAKENS YOUR IMMUNE SYSTEM? Not getting enough sleep Not eating right Pathogens attacking the immune system Malnutrition Obesity Drug Abuse

What are some things you can do to strengthen your immune system? Write it down here:

What exactly is cancer? Cells continue to grow and divide out of control… they don’t die when they’re supposed to A tumor is a lump of cancer cells that can destroy normal cells around the tumor and damage healthy tissues Cancer cells can break away from the original tumor and travel to other parts of the body. This is how cancer spreads Source: pictures.com/cancer/images/cancer- cell.jpg

RELATIONSHIP BETWEEN IMMUNE SYSTEM AND CANCER CELLS Cancer cells suppress immune system functioning Old thinking: Immune system ignores cancer cells, and cancer cells completely shut down the immune system New understanding: The immune system CAN still be activated, as we see from the presence of B cells, T cells, and dendritic cells around tumor cells. Current research is trying to better understand the relationship between the immune system and cancer cells