Immunity QuestionsImmunity QuestionsLymphatic/Immune SystemLymphatic/Immune System

6-10, 13, 17-266-10, 13, 17-26

6) What are the two intrinsic 6) What are the two intrinsic (nonspecific) defense systems of (nonspecific) defense systems of the body?the body? First line of defenseFirst line of defense

Skin and mucous membranesSkin and mucous membranes Second line of defenseSecond line of defense

Nonspecific cellular and chemical Nonspecific cellular and chemical protection devicesprotection devices

(Third line of defense = specific (Third line of defense = specific immune responses to kill particular immune responses to kill particular organisms)organisms)

First line of defenseFirst line of defenseSkin and mucous membranesSkin and mucous membranes

Skin has 4 ways to block entry of diseaseSkin has 4 ways to block entry of disease1.1. StructureStructure

Dead, dried out keratinized cells – waterproof Dead, dried out keratinized cells – waterproof barrierbarrier

2.2. Continuously replaced – Continuously replaced – pathogens get sloughed off pathogens get sloughed off

3.3. AcidicAcidic pH 5-6 is hostile environmentpH 5-6 is hostile environment

4.4. Sweat glands produce antibodiesSweat glands produce antibodies Dermicidin kills a wide range of harmful Dermicidin kills a wide range of harmful

bacteriabacteria

Mucus and other secretionsMucus and other secretions

Tears, saliva, earwaxTears, saliva, earwax Tears & saliva contain lysozyme = Tears & saliva contain lysozyme =

bacteria killerbacteria killer Earwax traps particlesEarwax traps particles

Mucus secreted in GI tract, Mucus secreted in GI tract, respiratory tract mires respiratory tract mires microorganismsmicroorganisms Cilia beat constantly and sweep away Cilia beat constantly and sweep away

pathogens (coughed up or swallowed)pathogens (coughed up or swallowed)

Mucus and other secretions cont’dMucus and other secretions cont’d

Digestive and vaginal acids – low pH Digestive and vaginal acids – low pH hostile environmenthostile environment

Vomiting, urination, defecation all Vomiting, urination, defecation all remove microorganismsremove microorganisms Urine is acidicUrine is acidic Vomiting cleans the stomachVomiting cleans the stomach Diarrhea speeds pathogen expulsionDiarrhea speeds pathogen expulsion

Second line of defenseSecond line of defenseNonspecific cellular and chemical Nonspecific cellular and chemical

protection devicesprotection devices White blood cell army are Generalists – White blood cell army are Generalists –

attack everything, clean up and repair crewattack everything, clean up and repair crew Phagocystosis – captures and digestsPhagocystosis – captures and digests

1.1. Neutrophils – first to respond, digest, Neutrophils – first to respond, digest, destroydestroy

2.2. Macrophages – engulf and digest large Macrophages – engulf and digest large numbers of invadersnumbers of invaders

3.3. Eosinophils – cluster around large parasites Eosinophils – cluster around large parasites and bombard with digestive enzymesand bombard with digestive enzymes

7) What is the innate (specific) 7) What is the innate (specific) system? What are the two lines of system? What are the two lines of defense of this system?defense of this system?

Third line of defenseThird line of defense T-cells and B-cells mount attack against T-cells and B-cells mount attack against

particular foreign substancesparticular foreign substances

8) What is the most important 8) What is the most important mechanism for inhibiting the spread mechanism for inhibiting the spread of invaders throughout the body? of invaders throughout the body? What does it do?What does it do? Inflammatory response-redness, warmth, swelling and painInflammatory response-redness, warmth, swelling and pain Starts when tissue is damagedStarts when tissue is damaged Chemical stimulus calls mast cells (connective tissue) to Chemical stimulus calls mast cells (connective tissue) to

release histaminerelease histamine Histamine causes vasodilation & vessels are more Histamine causes vasodilation & vessels are more

permeable allowing phagocytes to enter battle along with permeable allowing phagocytes to enter battle along with more blood more blood swelling, redness, warmth swelling, redness, warmth

Extra fluid dilutes pathogens and toxins & brings in clotting Extra fluid dilutes pathogens and toxins & brings in clotting proteins to wall off damaged areaproteins to wall off damaged area

Extra oxygen and nutrients promote tissue healing and Extra oxygen and nutrients promote tissue healing and carries away damaged cells, microorganisms and debriscarries away damaged cells, microorganisms and debris

Swollen tissue press on nerves causing pain – reduces Swollen tissue press on nerves causing pain – reduces movementmovement

9) What does fever do?9) What does fever do?

High body High body temperature temperature inhibits microbial inhibits microbial multiplication and multiplication and enhances body enhances body repair processrepair process

Good for Good for moderate body moderate body temp <103 temp <103

10) What does the adaptive 10) What does the adaptive (specific) defense system do? What (specific) defense system do? What cells participate in this process?cells participate in this process? Works in conjunction with the Works in conjunction with the

intrinsic: intrinsic: it identifies the specific invader, it identifies the specific invader, participates in the specific invader's participates in the specific invader's

destruction by either destruction by either killing them directly killing them directly activating the inflammatory response activating the inflammatory response activating complement proteins activating complement proteins making antibodiesmaking antibodies

Lymphocytes role (10)Lymphocytes role (10)

T cells participate in adaptive cellular T cells participate in adaptive cellular defense (kill or help with the kill)defense (kill or help with the kill)

B cells make antibodies that help B cells make antibodies that help with the destruction of the invaderwith the destruction of the invader

13) What is a bubo? What is the 13) What is a bubo? What is the causative agent of the bubonic causative agent of the bubonic plague?plague?

A swelling of the lymph nodes that A swelling of the lymph nodes that can look like a blister usually in the can look like a blister usually in the armpit, groin or neckarmpit, groin or neck

In bubonic plague the causative In bubonic plague the causative agent is a bacterium carried by fleas agent is a bacterium carried by fleas on rats and may have originated in on rats and may have originated in the Gobi Desert in 14the Gobi Desert in 14thth century century

17) Give the steps of the B-cell 17) Give the steps of the B-cell (humoral) immune response. (humoral) immune response. Antibody mediated immunity or humoral Antibody mediated immunity or humoral

immunity because it takes place in the immunity because it takes place in the blood (humor = blood)blood (humor = blood)

B cellsB cells from bone marrow move into from bone marrow move into lymphatic tissues/organs and lymphatic tissues/organs and become become plasma cellsplasma cells (cells transported by the (cells transported by the plasma) plasma) that produce antibodiesthat produce antibodies (antibodies are proteins capable of (antibodies are proteins capable of inactivating antigens)inactivating antigens)

B cells must be activated by helper T cellsB cells must be activated by helper T cells Antibodies are secreted into the blood, Antibodies are secreted into the blood,

lymph and mucus – they combine with the lymph and mucus – they combine with the antigen and mark them for destructionantigen and mark them for destruction

B cell immune response cont’d B cell immune response cont’d

Once antibody production is enough Once antibody production is enough to cause the antigen to disappear the to cause the antigen to disappear the development of the plasma cells development of the plasma cells stopsstops

Some cells remain (memory B cells) Some cells remain (memory B cells) in case of future invasion = active in case of future invasion = active immunityimmunity

18) What is an antibody, what does 18) What is an antibody, what does it do, and what is its structure?it do, and what is its structure? Immunoglobulins Immunoglobulins Soluble proteins secreted by activated Soluble proteins secreted by activated

B cells and plasma cells in response to B cells and plasma cells in response to an antigenan antigen

Capable of combining with and Capable of combining with and inactivating antigensinactivating antigens

Consists of 4 looping polypeptide Consists of 4 looping polypeptide chainschains 2 heavy, 2 light that combine to form the 2 heavy, 2 light that combine to form the

antigen-binding site – Y shapeantigen-binding site – Y shape

19) What are the general functions 19) What are the general functions of an antibody?of an antibody?1.1. activate complement proteins (starts activate complement proteins (starts

a series of reactions resulting in holes a series of reactions resulting in holes formed in bacterial cell walls formed in bacterial cell walls lysis) lysis)

2.2. enhance phagocytosis and enhance phagocytosis and inflammationinflammation

3.3. neutralize pathogensneutralize pathogens

4.4. cause pathogens to “clump” togethercause pathogens to “clump” together

5.5. lead to pathogen destruction but do lead to pathogen destruction but do not directly destroy the pathogen!not directly destroy the pathogen!

20) What is the function of a 20) What is the function of a memory cell?memory cell? B cell division also produces memory B cell division also produces memory

cells along with plasma cells but cells along with plasma cells but memory cells don’t produce antibodiesmemory cells don’t produce antibodies

They stay in the lymph in case they They stay in the lymph in case they encounter their particular bacterium encounter their particular bacterium againagain

If prompted by an activated helper T-If prompted by an activated helper T-cell more plasma cells will be cell more plasma cells will be produced and wipe out invaders produced and wipe out invaders before we feel any symptomsbefore we feel any symptoms

21) Describe the primary and 21) Describe the primary and secondary response. Why are secondary response. Why are vaccinations so, so important??? vaccinations so, so important???

Primary immune response – when Primary immune response – when pathogen enters the body = antigen pathogen enters the body = antigen challengechallenge

3-6 days immune response starts3-6 days immune response starts B cells proliferate and become plasma B cells proliferate and become plasma

cells (antibody factories)cells (antibody factories) Plasma antibody peak reached in 10 Plasma antibody peak reached in 10

daysdays

Secondary immune responseSecondary immune response

Occurs the second time we are Occurs the second time we are exposed to the antigenexposed to the antigen

Faster because immune system has Faster because immune system has been “trained” already (memory been “trained” already (memory cells)cells)

Plasma antibody peak reached 2-3 Plasma antibody peak reached 2-3 daysdays

Importance of vaccinesImportance of vaccines

Artificially acquired immunityArtificially acquired immunity Shot gives you exposure to Shot gives you exposure to

deactivated pathogen causing deactivated pathogen causing production of memory cellsproduction of memory cells

22) What is active immunity? How 22) What is active immunity? How can it be acquired?can it be acquired? Occurs when b cells encounter Occurs when b cells encounter

antigens and produce antibodiesantigens and produce antibodies Artificially acquired – vaccineArtificially acquired – vaccine Naturally acquired – natural contactNaturally acquired – natural contact

23) What is a vaccination? What 23) What is a vaccination? What can you do to reduce the side can you do to reduce the side effects of a vaccination? effects of a vaccination?

Part of a pathogen or some altered Part of a pathogen or some altered version of it is introduced to your version of it is introduced to your system in small amountsystem in small amount

Benefits: spare us discomfort (or Benefits: spare us discomfort (or death); creates memory cellsdeath); creates memory cells

Reduce symptoms with Reduce symptoms with antihistaminesantihistamines

24) What is a booster shot? What 24) What is a booster shot? What is its purpose?is its purpose? Second shot of same vaccineSecond shot of same vaccine Intensifies immune response with a Intensifies immune response with a

second exposuresecond exposure Can cause mild illness or allergic Can cause mild illness or allergic

reactionreaction

25) What is passive immunity? 25) What is passive immunity? How do you get it?How do you get it? Antibodies are obtained from the serum of Antibodies are obtained from the serum of

an immune personan immune person B cells do not produce new antibodies B cells do not produce new antibodies

(there is no antigen challenge) – so no (there is no antigen challenge) – so no memory cells are madememory cells are made

Protection ends when donor antibodies Protection ends when donor antibodies degrade – but search and destroy while degrade – but search and destroy while presentpresent

Mother to fetus, breast feedingMother to fetus, breast feeding Snake bite serum, rabies shotsSnake bite serum, rabies shots

26) What are monoclonal 26) What are monoclonal antibodies? What is their promise?antibodies? What is their promise? Serum sickness can be a side effect of Serum sickness can be a side effect of

passive immunity – proteins in the serum passive immunity – proteins in the serum are recognized as foreignare recognized as foreign

Monoclonal antibodies are made in the lab Monoclonal antibodies are made in the lab using patient lymphocytes (exposed in using patient lymphocytes (exposed in vitro – in glassware) to a particular antigenvitro – in glassware) to a particular antigen

Fused with a cancer cell that continuously Fused with a cancer cell that continuously divides making a lot of antibodies that divides making a lot of antibodies that won’t cause serum sicknesswon’t cause serum sickness