U3: C10: Immune System

Question 1

Innate vs adaptive comparison (def only)

Answer 1

1. innate: first line of defense, kills anything that doesn’t look right, is not specific to pathogen or antigen 2. adaptive: highly specific for a particular pathogen or antigen

Question 2

Innate immune players

Answer 2

1: skin: natural flora, keratin layers 2. mucus membrane: traps pathogens in mucus, and cilia moves it out 3. Phagocytes: engulf pathogens 4. Natural Killer cells: destroy infected cells 5. Antimicrobial proteins: tears, interferons, complement 6. fever/inflammation: WBCs are more active at higher temperature, and inflammation recruits wbcs to sites of infection by sending out chemical signals and making capillaries more permeable.

Question 3

Antimicrobial Proteins

Answer 3

innate immune system 1. tears (lyse bacteria), 2. interferons (interfere with virus replication), 3. complement (punches holes in cell/pathogen membrane),

Question 4

Adative immunity players

Answer 4

1. Antigen presenting cells (APC): 2. Antigen recognizing cells (ARC): T and B cells 3. Cytotoxic T cells: kill infected cells 4. Helper T cells: activate macrophages, T and B cells 5. B cells: produce antibodies 6. Memory cells: made and are more efficient (don’t need T cell activation) in proliferating and making antibodies for same infection in future.

Question 5

Memory cells

Answer 5

allow the body to mount a greater, and more sustained response against the same pathogen during 2ndary response.

Question 6

Anitbody mechanism for destroying pathogens

Answer 6

Antibody binding to antigen brings about.. 1. neutralization: pathogen can’t adhere to host cell 2. opsonization: makes it easier for phagocytosis 3. complement activation: kills infected cell by punching holes in cell membrane

Question 7

Antibody and Antigen structure 1. Antibody 2. Antigen 3. Light vs Heavy chain 4. Binding region

Answer 7

Antibody (lock), Antigen (key) each antibody is specific to the binding of an antigen 1. Y shaped, with heavy and light chains. the tips of the fork bind antigen. Fork = hypervariable region = unique to each antigen-specific antibody.l 2. Presented by… a. pathogen enters APC b. pieces of pathogen displayed at the surface of APCs c. T cell receptors recognize the presented antigen, and activates various immune responses. 3. light chain and heavy chain linked togehter by disulfide bonds 4. hypervariable region (light and heavy chain)

Question 8

Extracellular pathogen

Answer 8

1. macrophage engulfs pathogen 2. pieces of pathogen become antigen and gets presented at the macrophage’s cell surface 3. helper T cell recognize the presented antigen, and activates macrophages to destroy pathogen. Helper T cells also activate B cells to produce antibodies against the pathogen.

Question 9

Intracellular pathogen

Answer 9

1. pathogen invade host cell 2. pieces of pathogen gets presented on the host cell surface 3. cytotoxic T cells recognize the presented antigen, and signals the infected cell to self destruct

Question 10

Leukocytes origins and divisions

Answer 10

http://mcat-review.org/leukocytes.gif

Question 11

Lymphocytes

Answer 11

T cell: cytotoxic T cell, helper T cell B cell: plasma cell, memory cell Natural killer cells

Question 12

Phagocytes

Answer 12

neutrophil, macrophage, dendritic cell

Question 13

Antigen presenting cells

Answer 13

Macrophages, Dendritic cells, B cells

Question 14

Tissue x 4

Answer 14

bone marrow, spleen, thymus, lymph nodes

Question 15

bone marrow

Answer 15

all blood cells arise from stem cells from here, B lymphocytes differentiate in the bone marrow

Question 16

spleen

Answer 16

provides a site for WBCs to reside and proliferate, removes pathogens from blood, and grave yard for RBCs and platlets

* filers blood and lymph and storage area for blood

Question 17

thymus

Answer 17

T lymphocytes differentiate occurs here

*secretes thymosin- hormoe that stimulates pre-T cells to mature

Question 18

lymph nodes

Answer 18

provide a site for WBCs to reside and proliferate, remove pathoges from lymph. Residing lymphocytes monitor lymph for foreign antigens, and initiate an immune response when exposed to foreign antigens

*filter lymph and help attack bacteria and viruses

Question 19

macrophage

Answer 19

myeloid -> monocyte phagocytose pathogens and APC

Question 20

neutrophils

Answer 20

myeloid -> polymorphonuclear leukocytes phagocytose pathogens and destroy it

Question 21

mast cells

Answer 21

myeloid release histamine during allergic response, bring about inflammation

Question 22

NK cells

Answer 22

lymphoid kills infected & abnormal cells

Question 23

B lymphocytes 1. matures 2. plasma cell 3. memory cell

Answer 23

1. bone marrow B cells only form 2 and 3 after exposure to antigen 2. secrete antibody 3. stick around in case the same antigen attaks in the future

Question 24

dendritic cells

Answer 24

myeloid -> monocyte best APC

Question 25

T lymphocytes 1. matures where 2. cytotoxic T cell 3. helper T cell

Answer 25

1. thymus 2. recognize antigen on infected cells, and signal for apoptosis 3. recognize antigen on APCs, and signal for activation of B & T cells, and macrophages

Question 26

____ are the functional cells of the immune syste. They consist of ____ (neutrophil, eosinophil, basophil) & ____ (lymphocytes & monocytes)

Answer 26

leukocytes, granulocytes, agranulocytes

Question 27

humoral immunity is mediated by ____. Function..

Answer 27

B cells. B cell proliferate to make plasma cells (antibodies) and memory cells

Question 28

Cell mediated immunity is mediated by ____. Function..

Answer 28

T cells. 3 major classes (helper T cells, supressor T cells, and killer T cells (cytotoxic) (also a memory T cell)

Question 29

Active vs passive Immunization

Answer 29

Active: results in a sustained immune response mediated by B cells (antibodies formed from by b cells) Passive: short lived response (injection of antibodies)

Question 30

Natural vs artifical immunization

Answer 30

natural: exposure to antigen in nature or trasfer of anitbodies from mother to fetus Artificial: is an active immunization that uses weakend or dead forms of microbes to generate an immune response without causing active infection

Question 31

Which (humoral/ cell mediated) immune system combat these pathogens best? 1. bacterial infections 2. viral infections 3. fungal infecctions

Answer 31

1. humoral (B) 2. cell mediated (T) 3. cell mediated (T)

Question 32

Adaptive Immunity: memory response

Answer 32