1. Immunity Questions Lymphatic/Immune System 6-10, 13, 17-26

2. 6) What are the two intrinsic (nonspecific) defense systems of the body? First line of defense First line of defense Skin and mucous membranes Skin and mucous membranes Second line of defense Second line of defense Nonspecific cellular and chemical protection devices Nonspecific cellular and chemical protection devices (Third line of defense = specific immune responses to kill particular organisms) (Third line of defense = specific immune responses to kill particular organisms)

3. First line of defense Skin and mucous membranes Skin has 4 ways to block entry of disease Skin has 4 ways to block entry of disease 1. Structure Dead, dried out keratinized cells – waterproof barrier Dead, dried out keratinized cells – waterproof barrier 2. Continuously replaced – pathogens get sloughed off pathogens get sloughed off 3. Acidic pH 5-6 is hostile environment pH 5-6 is hostile environment 4. Sweat glands produce antibodies Dermicidin kills a wide range of harmful bacteria Dermicidin kills a wide range of harmful bacteria

4. Mucus and other secretions Tears, saliva, earwax Tears, saliva, earwax Tears & saliva contain lysozyme = bacteria killer Tears & saliva contain lysozyme = bacteria killer Earwax traps particles Earwax traps particles Mucus secreted in GI tract, respiratory tract mires microorganisms Mucus secreted in GI tract, respiratory tract mires microorganisms Cilia beat constantly and sweep away pathogens (coughed up or swallowed) Cilia beat constantly and sweep away pathogens (coughed up or swallowed)

5. Mucus and other secretions cont’d Digestive and vaginal acids – low pH hostile environment Digestive and vaginal acids – low pH hostile environment Vomiting, urination, defecation all remove microorganisms Vomiting, urination, defecation all remove microorganisms Urine is acidic Urine is acidic Vomiting cleans the stomach Vomiting cleans the stomach Diarrhea speeds pathogen expulsion Diarrhea speeds pathogen expulsion

6. Second line of defense Nonspecific cellular and chemical protection devices White blood cell army are Generalists – attack everything, clean up and repair crew White blood cell army are Generalists – attack everything, clean up and repair crew Phagocystosis – captures and digests Phagocystosis – captures and digests 1. Neutrophils – first to respond, digest, destroy 2. Macrophages – engulf and digest large numbers of invaders 3. Eosinophils – cluster around large parasites and bombard with digestive enzymes

7. 7) What is the innate (specific) system? What are the two lines of defense of this system? Third line of defense Third line of defense T-cells and B-cells mount attack against particular foreign substances T-cells and B-cells mount attack against particular foreign substances

8. 8) What is the most important mechanism for inhibiting the spread of invaders throughout the body? What does it do? Inflammatory response-redness, warmth, swelling and pain Inflammatory response-redness, warmth, swelling and pain Starts when tissue is damaged Starts when tissue is damaged Chemical stimulus calls mast cells (connective tissue) to release histamine Chemical stimulus calls mast cells (connective tissue) to release histamine Histamine causes vasodilation & vessels are more permeable allowing phagocytes to enter battle along with more blood  swelling, redness, warmth Histamine causes vasodilation & vessels are more permeable allowing phagocytes to enter battle along with more blood  swelling, redness, warmth Extra fluid dilutes pathogens and toxins & brings in clotting proteins to wall off damaged area Extra fluid dilutes pathogens and toxins & brings in clotting proteins to wall off damaged area Extra oxygen and nutrients promote tissue healing and carries away damaged cells, microorganisms and debris Extra oxygen and nutrients promote tissue healing and carries away damaged cells, microorganisms and debris Swollen tissue press on nerves causing pain – reduces movement Swollen tissue press on nerves causing pain – reduces movement

9. 9) What does fever do? High body temperature inhibits microbial multiplication and enhances body repair process High body temperature inhibits microbial multiplication and enhances body repair process Good for moderate body temp <103 Good for moderate body temp <103

10. 10) What does the adaptive (specific) defense system do? What cells participate in this process? Works in conjunction with the intrinsic: Works in conjunction with the intrinsic: it identifies the specific invader, it identifies the specific invader, participates in the specific invader's destruction by either participates in the specific invader's destruction by either killing them directly killing them directly activating the inflammatory response activating the inflammatory response activating complement proteins activating complement proteins making antibodies making antibodies

11. Lymphocytes role (10) T cells participate in adaptive cellular defense (kill or help with the kill) T cells participate in adaptive cellular defense (kill or help with the kill) B cells make antibodies that help with the destruction of the invader B cells make antibodies that help with the destruction of the invader

12. 13) What is a bubo? What is the causative agent of the bubonic plague? A swelling of the lymph nodes that can look like a blister usually in the armpit, groin or neck A swelling of the lymph nodes that can look like a blister usually in the armpit, groin or neck In bubonic plague the causative agent is a bacterium carried by fleas on rats and may have originated in the Gobi Desert in 14 th century In bubonic plague the causative agent is a bacterium carried by fleas on rats and may have originated in the Gobi Desert in 14 th century

13. 17) Give the steps of the B-cell (humoral) immune response. Antibody mediated immunity or humoral immunity because it takes place in the blood (humor = blood) Antibody mediated immunity or humoral immunity because it takes place in the blood (humor = blood) B cells from bone marrow move into lymphatic tissues/organs and become plasma cells (cells transported by the plasma) that produce antibodies (antibodies are proteins capable of inactivating antigens) B cells from bone marrow move into lymphatic tissues/organs and become plasma cells (cells transported by the plasma) that produce antibodies (antibodies are proteins capable of inactivating antigens) B cells must be activated by helper T cells B cells must be activated by helper T cells Antibodies are secreted into the blood, lymph and mucus – they combine with the antigen and mark them for destruction Antibodies are secreted into the blood, lymph and mucus – they combine with the antigen and mark them for destruction

16. B cell immune response cont’d Once antibody production is enough to cause the antigen to disappear the development of the plasma cells stops Once antibody production is enough to cause the antigen to disappear the development of the plasma cells stops Some cells remain (memory B cells) in case of future invasion = active immunity Some cells remain (memory B cells) in case of future invasion = active immunity

17. 18) What is an antibody, what does it do, and what is its structure? Immunoglobulins Immunoglobulins Soluble proteins secreted by activated B cells and plasma cells in response to an antigen Soluble proteins secreted by activated B cells and plasma cells in response to an antigen Capable of combining with and inactivating antigens Capable of combining with and inactivating antigens Consists of 4 looping polypeptide chains Consists of 4 looping polypeptide chains 2 heavy, 2 light that combine to form the antigen-binding site – Y shape 2 heavy, 2 light that combine to form the antigen-binding site – Y shape

19. 19) What are the general functions of an antibody? 1. activate complement proteins (starts a series of reactions resulting in holes formed in bacterial cell walls  lysis) 2. enhance phagocytosis and inflammation 3. neutralize pathogens 4. cause pathogens to “clump” together 5. lead to pathogen destruction but do not directly destroy the pathogen!

21. 20) What is the function of a memory cell? B cell division also produces memory cells along with plasma cells but memory cells don’t produce antibodies B cell division also produces memory cells along with plasma cells but memory cells don’t produce antibodies They stay in the lymph in case they encounter their particular bacterium again They stay in the lymph in case they encounter their particular bacterium again If prompted by an activated helper T-cell more plasma cells will be produced and wipe out invaders before we feel any symptoms If prompted by an activated helper T-cell more plasma cells will be produced and wipe out invaders before we feel any symptoms

22. 21) Describe the primary and secondary response. Why are vaccinations so, so important??? Primary immune response – when pathogen enters the body = antigen challenge Primary immune response – when pathogen enters the body = antigen challenge 3-6 days immune response starts 3-6 days immune response starts B cells proliferate and become plasma cells (antibody factories) B cells proliferate and become plasma cells (antibody factories) Plasma antibody peak reached in 10 days Plasma antibody peak reached in 10 days

23. Secondary immune response Occurs the second time we are exposed to the antigen Occurs the second time we are exposed to the antigen Faster because immune system has been “trained” already (memory cells) Faster because immune system has been “trained” already (memory cells) Plasma antibody peak reached 2-3 days Plasma antibody peak reached 2-3 days

24. Importance of vaccines Artificially acquired immunity Artificially acquired immunity Shot gives you exposure to deactivated pathogen causing production of memory cells Shot gives you exposure to deactivated pathogen causing production of memory cells

25. 22) What is active immunity? How can it be acquired? Occurs when b cells encounter antigens and produce antibodies Occurs when b cells encounter antigens and produce antibodies Artificially acquired – vaccine Artificially acquired – vaccine Naturally acquired – natural contact Naturally acquired – natural contact

26. 23) What is a vaccination? What can you do to reduce the side effects of a vaccination? Part of a pathogen or some altered version of it is introduced to your system in small amount Part of a pathogen or some altered version of it is introduced to your system in small amount Benefits: spare us discomfort (or death); creates memory cells Benefits: spare us discomfort (or death); creates memory cells Reduce symptoms with antihistamines Reduce symptoms with antihistamines

27. 24) What is a booster shot? What is its purpose? Second shot of same vaccine Second shot of same vaccine Intensifies immune response with a second exposure Intensifies immune response with a second exposure Can cause mild illness or allergic reaction Can cause mild illness or allergic reaction

28. 25) What is passive immunity? How do you get it? Antibodies are obtained from the serum of an immune person Antibodies are obtained from the serum of an immune person B cells do not produce new antibodies (there is no antigen challenge) – so no memory cells are made B cells do not produce new antibodies (there is no antigen challenge) – so no memory cells are made Protection ends when donor antibodies degrade – but search and destroy while present Protection ends when donor antibodies degrade – but search and destroy while present Mother to fetus, breast feeding Mother to fetus, breast feeding Snake bite serum, rabies shots Snake bite serum, rabies shots

29. 26) What are monoclonal antibodies? What is their promise? Serum sickness can be a side effect of passive immunity – proteins in the serum are recognized as foreign Serum sickness can be a side effect of passive immunity – proteins in the serum are recognized as foreign Monoclonal antibodies are made in the lab using patient lymphocytes (exposed in vitro – in glassware) to a particular antigen Monoclonal antibodies are made in the lab using patient lymphocytes (exposed in vitro – in glassware) to a particular antigen Fused with a cancer cell that continuously divides making a lot of antibodies that won’t cause serum sickness Fused with a cancer cell that continuously divides making a lot of antibodies that won’t cause serum sickness