1. Ch. 11 Immunity Part 1

2. EXPLAIN Immune Response EXPLAIN effective use of antibiotics and describe bacterial resistance DEFINE Antigen Self Non-self RELATE the molecular STRUCTURE of antibodies to their FUNCTION EXPLAIN the role of memory cells in long term immunity DISTINGUISH between ACTIVE immunity and PASSIVE immunity EXPLAIN how vaccination can control disease DISCUSS the reasons vaccination has eradicated small pox but NOT measles, malaria, TB, sickle cell anemia, or cholera Be able to:

3. Non-infectious disease Diseases NOT caused by pathogens Genetic, deficiency, environment Lung cancer, COPD, CHD, allergies, asthma Infectious Disease Diseases caused by organisms known as pathogens Communicable diseases When pathogens are passed from an infected person to a non-infected person Can be passed from animals to humans Pathogen Organisms and agents that cause infectious disease; Describe something that can be passed from one organism to another Examples: Bacteria, fungi, and protists, viruses Why is the statement “transmission of a pathogen from an infected person to a non-infected person” preferable to “the disease passes from one person to another”? Disease: an illness or disorder of the body that leads to poor health; associated with set of symptoms; disrupts normal function of body (other than injury)

4. Disease disrupts stability of an organisms STABLE INTERNAL environment Immune systems helps MAINTAIN stability…AKA HOMEOSTASIS Immune System: The organ system that protects the body from disease Made up of specialized cells and organs that work together to protect you from pathogens Infection- the multiplication of a pathogen in body tissue Three different lines of defense 2 categories External defense Barriers Internal Defense Inflammatory Response Immune Response The Immune System What is homeostasis? Why do you think the immune system plays a role in homeostasis? Your Body Fighting Against Evil Invaders!

5. INNATE Immunity -Rapid responses to a broad range of microbes -What you are born with; non-specific ACQUIRED/ADAPTIVE immunity -Slower responses to specific microbes -ACTIVE and PASSIVE (artificial and natural) External DefensesInternal Defenses Skin Mucous membranes Secretions Phagocytic cells Antimicrobial proteins Inflammatory response Natural Killer cells Humoral response (antibodies) Cell-mediated response (cytotoxic lymphocytes) Types of Immunity

6. Nonspecific vs. specific defenses Nonspecific defenses do not distinguish one infectious microbe from another Physical defenses Chemical defenses Cellular defenses Examples: Epithelia in air ways HCL in stomach Blood clotting Specific defenses recognize and defend against invading microbes and cancer cells Involves presence of an antigen Non-self antigen: Molecule body recognizes as foreign White Blood Cells recognize non-self-antigens 2 major types of White Blood Cells 1. Phagocytes 2. Lymphocytes Immune Response Complex series of responses of the body to the entry of a foreign antigen Involves activity of lymphocytes and phagocytes

8. Nonspecific defenses Skin Mucus Macrophages Inflammatory Response Interferons and complement proteins attack microbes either directly or indirectly by impeding their reproduction Interferons are produced by infected cells Diffuse to healthy cells where they cause the cell to inhibit viral production Complement proteins are activated by microbes or immune system Coat infected cells –easier to eat Can amplify inflammatory response

9. Nonspecific defenses: inflammatory response

10. Redness, heat, and swelling caused by Increase in blood flow, fluid, and cells Inflammatory response disinfects and cleans injured tissues Pus = dead white cells and fluid Systemic response is widespread Toxins or microorganisms released in bloodstream Circulates through body Inflammatory weapons increase white blood cells, Fever Low-grade fever can stimulate phagocytosis and inhibit growth of many microorganisms

11. Specific immunity Often more effective than nonspecific response It also amplifies nonspecific response Specific response begins due to presence of an antigen Can either increase # of cells that attack invader directly OR Produce antibodies Antibodies  GLYCOPROTEIN molecules that act against specific antigens Immune system “remembers” antigens it has previously encountered Responds immediately and vigorously Is adaptive

12. ANTIGENS…. different types Any molecule which the body recognizes as foreign Cell surface antigens : molecules found on the surface of our own cell membranes Different from other animals AND sometimes other humans Self Antigens Antigens that your body recognizes as belonging to YOU your body will NOT produce antibodies against it Non-Self Antigens Antigens that your body does NOT recognize as belonging to you Your body WILL produces antibodies against it so WBC can attack and destroy Immune Response Response of lymphocytes ( T cells and B cells) to the presence of a foreign (non-self) antigen Involves two methods of attack: Lymphocytes produce ANTIBODIES against ANTIGEN Kill cells that have been infected or the actual invader them self

14. You have to make ANTIBODIES!!! Remember those? Definition: protein produced by white blood cells (WBCS) Also called: IMMUNOGLOBINS Attaches to antigens of invaders using ”lock and key” mechanism ANTIGENS: large molecules (either proteins or polysaccharides)on the surface of cells and viruses -(Have a specific shape) Antibodies cause pathogens to clump together=easier for your body to attack and destroy Well how does our body do that? Two different ways…. Active Immunity Passive Immunity How Do We Build Immunity? Your body marks the attackers, herds them together, and DESTROYS them!

16. Antibodies Globular glycoproteins Form a group of plasma proteins called Immunoglobulins (Ig) Basic molecule common to all antibodies consists of 4 polypeptide chains Two long/ heavy chains Two short/light chains Disulfide bridges hold the chains together Each molecule has two identical antigen binding sites (that are formed by both heavy and light chains) The sequences of a.a. in this region make a specific 3D shape of the protein that attaches to one specific antigen… VARIABLE REGION Hinge region gives antibodies flexibility to bind around antigen

20. 6 MAJOR Functions of Antibodies 1. Combine with viruses and bacterial toxins preventing them entering or damaging cells 2. Attach to the flagella making them less active and easier for phagocytes to engulf 3. Antibodies with multiple antigen binding sites cause agglutination of bacteria reducing the chances of spread throughout the body 4. Together with other molecules, some antibodies “ punch ” holes in the cells wall as of bacteria causing them to burst when they absorb water by osmosis 5. Coat bacteria making it easier for phagocytes to ingest them; phagocytes have receptor proteins for heavy polypeptide chains of antibodies 6. combine with toxins, neutralizing them and making them harmless; these antibodies are called antitoxins

23. The Immune Systems 3 Lines of Defense

24. #1: Barriers to Infection (nonspecific) Function- keep invaders (pathogens) OUT of your body Skin Mucous membranes (respiratory tract) mucus traps pathogens cilia moves it out of your throat and nose or into stomach (sneeze, cough, swallow) Mucus, Saliva and tears contain enzyme lysozyme (enzyme that breaks down cell walls of bacteria) Perspiring (sweat and oil) liquid waste secreted from pores that contains acids, salts and enzymes that kill bacteria on surface of skin The Immune Systems 3 Lines of Defense

25. #2 Inflammatory Response (nonspecific) Function- respond to the invaders that have entered the body and have started to damage precious tissue White Blood Cells WBCs Several different types specialized to fight disease Blood vessels near injury widen (dilate) to let more blood flow to area of injury Plasma fills spaces between cells Plasma carries WBCs called MACROPHAGES to injury site MACROPHAGES- large WBCs that engulf and destroy pathogens and alert other immune cells Develop from monocytes Release cytokines  proteins that help activate lymphocytes Area is swollen b/c of increased blood flow Fever- increase in temp. makes more less suitable for growth of bacteria and MACROPHAGES work more efficiently

26. The Immune Systems 3 Lines of Defense #3: Immune Response (specific) Function- specialized attack on SPECIFIC pathogens that have invaded the body Many WBCs involved Macrophages, T cells, and B cells WBCs secrete antibodies, a protein that attaches to specific region of foreign substance called the antigen