Immune System Introduction System that helps fight off and destroy Cancer cells and pathogens System that helps fight off and destroy Cancer cells and pathogens Composed of many parts: Composed of many parts: * Spleen * Spleen * Lymph nodes * Lymph nodes * Thymus * Thymus * Bone marrow * Bone marrow * Lymphatic vessels * Lymphatic vessels * Lymphocytes or White * Lymphocytes or White Blood cells Blood cells

Pathogens What are Pathogens? Organisms that cause disease Infectious diseases are? Diseases that are caused by pathogens. When you have an infectious disease pathogens are inside your body causing harm Staphyloccocus aureus Staphyloccocus aureus Magnified 20,000X Magnified 20,000X About 1 um in size About 1 um in size What type of pathogen is Staph? What type of pathogen is Staph? BACTERIA BACTERIA

4 TYPES OF COMMON PATHOGENS Can you guess what they are? * Viruses * Fungi B Bacillus * Bacteria * Protists/Parasites Fungus

Immune System Made of different types of cells each with a specific job T These cells are called Lymphocytes or White blood cells or WBC’s Target specific Pathogens, Infected cells and Cancer cells Sometimes the Immune system attacks its body: * This is called Autoimmune Disease Example: Lupus Erythematosus Arthritis

Types of Lymphocytes 1. T - cells Identify Pathogens by recognizing their Antigens What is their job? To activate B-cells 2. B B B B cells Produce chemicals called Antibodies Pa th og en s

Types of Lymphocytes 3. Macrophages – Surround pathogen and Surround pathogen and digest or eat it digest or eat it Also called Phagocytes Also called Phagocytes

Types of T – cells There are the Two Types of special T– Cells 1. Natural Killers Cells 2. Cytotoxic Cells * Destroy pathogens after they are marked by antibodies * Destroy cells that are infected with a virus * Also recognize cancer cells and destroy them

What are Memory T- Cells ? What are Memory T- Cells ? They remember what type of antigens They remember what type of antigens are on a pathogen!!! are on a pathogen!!! Help immune system recognize the pathogen if it invades our body again!! Help immune system recognize the pathogen if it invades our body again!! AMAZING ! ! ! AMAZING ! ! !

ANTIGENS AND ANTIBODIES What are Antigens? Special proteins on the surface of pathogens and surface of our cells cells They are recognized by the Immune System Why? So the White blood cells know which pathogens they need to destroy!!!

What are Antibodies? What are Antibodies? Special proteins that recognize specific Antigens on Pathogens Special proteins that recognize specific Antigens on Pathogens Mark the pathogens for destruction by WBC’s Mark the pathogens for destruction by WBC’s

The Immune System to g et h er to T h e i m m u n e sy st e m in cl u d es T c el ls a n d B c el ls. T h e c el ls w or k fi g ht in fe ct io n s. H How do T- cells and B - cells work together to fight off pathogens and destroy infected cells?

What happens when a virus infects a cell? What do T-cellsdo? What happens when a virus infects a cell? What do T-cells do?

What is another job of the T- cells?.

So, why do B – cells produce antibodies? Because……

How does the Immune System work T- cells recognize bacterial or viral antigen. Some T- cells attack cells infected with pathogens Other T-cells signal B cells to produce antibodies Other T-cells signal B cells to produce antibodies. Antibodies attach to the antigens on virus or bacteria Lock & Key) (Lock & Key) Antibodies help phagocytes destroy the bacteria or virus H o w d o e s t h e I m m u n e S y st e m w o r k H o w d o e s t h e I m m u n e S y st e m w o r k

ImmunityHow doesaperson becomeimmunized?How doesapersonbecomeimmunized?. ImmunityHow doesaperson becomeimmunized?How doesapersonbecomeimmunized?. Immunity How does a person become immunized?

Two Types of Immunity Active Immunity Immune system produces antibodies on its own in response to a pathogen Passive Immunity A ntibodies are injected into a patient to help prevent a disease from a pathogen

Vaccines How do vaccines work? 1.They contain a weakened pathogen that stimulates production of antibodies without causing the that stimulates production of antibodies without causing the actual disease actual disease Example: The Flu shot Example: The Flu shot 2. Antibodies are already in the vaccine Your immune system doesn’t need to Your immune system doesn’t need to produce them produce them

Active Immunity Both Passive Immunity The body makes antibodies. Memory cells recognize antigens from the pathogen from the pathogen. Immunity may last for years or a lifetime. Antibodies are given, the body does not make antibodies. Immunity can be acquired from the mother during pregnancy. Immunity lasts only a few months. Can prevent diseases May involve an injection

Systemic Lupus erythematosus Chronic inflammatory condition Occurs when the body's tissues are attacked by its own immune system P People with lupus have unusual antibodies in their blood that attack their own body Lupus can cause disease of the skin, heart, lungs, kidneys, joints, and nervous system Eight times more common in women than in men

Who Gets Lupus? Anyone can get lupus But, more than 90% of people with lupus are women Your odds of getting the disease are higher if you are: * African-American, Latino, or Asian * Aged 15 to 45 * Related to someone with lupus

Classic symptoms of Lupus Butterfly-shaped rash across the Butterfly-shaped rash across the cheeks and bridge of the nose cheeks and bridge of the nose Nails crack or fall off Nails crack or fall off Fever and Fatigue Fever and Fatigue Light Sensitivity Light Sensitivity Hair Loss Hair Loss

Which Organs are affected by Lupus? Heart Heart Lung

Which Organs are affected by Lupus? Lungs Lungs

Which Organs are affected by Lupus? Kidneys Kidneys

Which Organs are affected by Lupus? Liver Liver

JOINTS Connective tissue in joints is also affected What type of Connective tissue? * Tendons – Attach muscles to bones * Ligaments – Attach bone to bone

Review Questions 1. Question: What is the function of the immune system? Answer: Helps fight off pathogens. 2. Question: Which 4 white blood cells or lymphocytes help destroy pathogens? Answer: Macrophages, B cells and T cells 3. Question: What is an antigen? Answer: Special protein on surface of pathogens recognized by the immune system

4. Question: What is an antibody? Answer: Special protein in the immune system that recognizes and attaches to a specific antigen on a pathogen and marks the pathogen for destruction. 5.Q uestion: Explain the difference between Active and Passive Immunity? Answer: * In Active immunity the immune system produces the antibodies * In Passive immunity the antibodies are injected into a patient to destroy the pathogens

Review Questions 6. Question: Which cells of the immune system produce antibodies? Answer: B cells 7. Question: Which cells produce B cells? Answer: T cells 8. Question: Name the 2 types of T- cells Answer: 1) Natural Killer cells 2) Cytotoxic cells 9. Question: What are memory T - cells? Answer: * They remember what type of antigens are on the surface of a pathogen * Help immune system recognize the pathogen if it invades our body again!!

10. Question: What are the 4 main functions of T- cells Answer: 1. Stimulate B-cells to produce antibodies 2. Destroy pathogens after they are marked by antibodies 3. Destroy cells that are infected with a virus 4. Also recognize cancer cells and destroy them 11. Question: What are the 4 common pathogens? Answer: Virus Bacteria Fungi Protists/parasites :

12. Question: Name 2 ways a vaccine works! Answer: 1. Contains a weakened pathogen that stimulates production of antibodies without causing the actual disease, or…………? 2. Antibodies are already in the vaccine to destroy pathogens, body doesn’t need to make antibodies 13. Question: Why can’t scientists produce an effective vaccine against HIV? Answer: Because the virus mutates or changes and the vaccine no longer works!!!!!