Everything You Wanted to Know About the Immune System…And More!!!

Keeping Pathogens OUT!!! Always exposed to pathogens! Body destroys most all of them Remember- some can be good! But many are bad news!

1st Line of Defense 5 major barriers

5 Barriers Tears- wash them away, chemicals that kill them Saliva- in your mouth Skin- protective barrier (can enter through cut, burn, or scrape) Mucus Membranes- tissues line nose, throat, mouth, eyes, openings (they trap pathogens) Stomach Acid- acid destroys it

Immune System Immune System- combo of body defenses that are made up of cells, tissues, and organs that fight off pathogens. kicks in when these 5 barriers don’t work 1. Non-Specific Response 2. Specific Response

Non-Specific Response When pathogens enter the body, immune system ATTACKS! **SAME no matter the pathogen** Inflammatory Response- if pathogen gets past 5 barriers (What are they??)   Phagosytes- special white blood cells that kill pathogens! How? - High blood pressure releases proteins that defend the body Interferons.- the proteins that stop the pathogen from reproducing and helps the cells fight infection.

Phagocytes

Non-Specific Inflammation- body’s response to injury or disease, resulting in a condition of swelling, pain, heat, and redness. **Occurs in the blood and the tissues  -Fever- happens when the infection spreads through your body. Body heats up- tells your body to make more white blood cells so it’s harder for pathogens to reproduce (fight the disease harder)

Specific Response The pathogen just got through 5 barriers and Non-Specific… This defense tailored to fight a specific pathogen Immune system both fights and “remembers” the pathogen so it is more likely to fight it off right away if it ever enters your body again Lymphatic System: the body uses this system to do it’s specific fighting

Lymphatic System Lymphocytes- Special white blood cells in lymph Secondary circulatory system that helps the body fight pathogens and maintain its fluid balance. This system circulates lymph, which has many lymphocytes and macrophages in them. Lymphocytes- Special white blood cells in lymph B Cells- formed in bone marrow (stop viruses from getting into cells to reproducing) T Cells- thymus gland (fight existing pathogens) NK Cells- Natural Killer Cell (attacks cancerous growths) Macrophages: Phagocytes that help lymphocytes identify these invaders

These Lymphocytes are activated when these macrophages recognize the part of a pathogen known as an antigen. Antigen- substances (part of the pathogen) that send the immune system into action. Body reacts to these antigens by making Antibodies Antibodies- proteins connect to antigens, keeping them from harming the body. Makes the antigen so it can’t reproduces

Immunity Thats why we get vaccinated- so we can develop antibodies. Immunity- your body’s ability to resist the pathogens that cause a particular disease Virus mutes and changes, therefore the previous vaccines are ineffective.