EXAM 1 Intro to Immunology and Generalized Responses to Infection

Question 1

what are the 5 roles of the immune system?

Answer 1

1. kill or control pathogens
2. control disease
3. repair tissue damage
4. organ development
5. maintain organ integrity and function

Question 2

pathogens damage tissues in what two major ways?

Answer 2

directly and indirectly

Question 3

what are the 3 ways that pathogens directly damage tissues?

Answer 3

• exotoxin production
• endotoxin
• direct cytopathic effect

Question 4

what are the 3 ways that pathogens indirectly damage tissues?

Answer 4

• immune complexes
• anti-host antibody
• cell-mediated immunity

Question 5

what is an exotoxin?

Answer 5

a pathogen-secreted toxin

Question 6

what is an endotoxin?

Answer 6

a toxic pathogen component

Question 7

describe the form diversity challenge that pathogens present to the immune system

Answer 7

there are roughly 1400 diverse forms of pathogens

Question 8

describe the life cycle diversity challenge that pathogens present to the immune system

Answer 8

• pathogens often infect multiple body compartments
• pathogen physiology changes with life cycle
• no single immune response type clears a pathogen
• ex. listeria monocytogenes infection

Question 9

describe the diverse routes of infection challenge that pathogens present to the immune system

Answer 9

• mouth and respiratory tract
• GI tract
• reproductive tract
• opportunistic pathogens - resident micriobiota
• external surface
• wounds and abrasions
• insect bites

Question 10

describe the challenge of rapid, targeted response over a broad domain that pathogens present to the immune system

Answer 10

• immune system has to respond to many insults in specific ways
  
  • ex. external wound vs. inhalation of pathogen

Question 11

what are the 4 recognition mechanisms of innate immunity?

Answer 11

• rapid response (hours)
• fixed
• limited number of specificities
• constant during response

Question 12

what are the 4 recognition systems of adaptive immunity?

Answer 12

• slow response (days to weeks)
• variable
• numerous highly selective specificies
• improve during response

Question 13

T or F

the innate and adaptive immune systems work together to fight infections

Answer 13

true

Question 14

what are the 6 cells of innate immunity?

Answer 14

• granulocytes
  
  • neutrophil
  • eosinophil
  • basophil
• monocytes
  
  • macrophage
  • dendritic cell
• mast cell

Question 15

what are the 4 cells of adaptive immunity?

Answer 15

• lymphocytes
  
  • T cells
  • B cells
• NK cells
• dendritic cells

Question 16

describe primary lymphoid organs

Answer 16

• where immune cells originate and develop
• tissues
  
  • bone marrow and thymus

Question 17

describe secondary lymphoid organs

Answer 17

• where adaptive immune responses are initiated
• where naive and mature B and T cells reside
• tissues:
  
  • lymph nodes, spleen, lymphatic system, organ-specific lymph node-like tissues

Question 18

immune cells use the ___ and ___ systems to reach tissues

Answer 18

cardiovascular and lymphatic

Question 19

describe lymphatic recirculation

Answer 19

• immune cells use the cardiovascular system and lymphatic system to reach tissues
• naive lymphocytes arrive at lymph nodes in arterial blood
• pathogens from the site of infection reach lymph nodes via lymphatics
• lymphocytes and lymph return to the blood via the lymphatics
• venous blood returns to the heart

Question 20

the adaptive immune system comes from a common ___ precursor

Answer 20

lymphoid

Question 21

the innate immune system comes from a common ___ precursor

Answer 21

myeloid

Question 22

the lymphatic system is a large ___ network

Answer 22

duct

Question 23

lymphocytes, NK cells, monocytes, granulocytes, and mast cells are collectively called what?

Answer 23

leukocytes

Question 24

what is lymph?

Answer 24

interstitial fluid that drains into the lymphatic system, and includes cells, pathogens, and waste

Question 25

the flow of lymph is \_\_\_

Answer 25

unidirectional

Question 26

describe the unidirectional flow of lymph

Answer 26

* valves * smooth muscle * pressure gradient * drains into the venous system

Question 27

lymph nodes allow ___ to browse drainage

Answer 27

lymphocytes

Question 28

what are the three stages of the generalized response to infection?

Answer 28

1. immediate innate 2. induced innate 3. adaptive

Question 29

what are immediate innate systems involved in the inflammatory response?

Answer 29

* barriers * antimicrobial peptides * complement

Question 30

describe the process of the inflammatory response?

Answer 30

* surface wound introduces bacteria, resident effector cells are activated to secrete cytokines * fluid, protein, and inflammatory cells leave blood and enter tissue * infected tissue becomes inflamed, causing redness, heat, swelling, and pain

Question 31

describe the induced innate immune response

Answer 31

* neutrophils are stored in the bone marrow and are released when needed to fight infection * they enter the infected tissue, where they engulf and kill bacteria * neutrophils die in the tissue and are engulfed/degraded by macrophages

Question 32

what are the 7 cell types of the induced innate immune response?

Answer 32

* neutrophils * monocytes * macrophages * dendritic cells * basophils * eosinophils * mast cells * NK cells

Question 33

of the induced innate cell types, which ones are resident in the tissue but require activation?

Answer 33

basophils, eosinophils, and mast cells

Question 34

what are the 3 primary antigen presenting cell types?

Answer 34

dendritic cells, macrophages, and B lymphocytes

Question 35

describe how naive lymphocytes are activated in lymph nodes

Answer 35

* mature, naive T and B cells reside in lymph nodes * pathogens are presented to lymphocytes in lymph nodes * activated lymphocytes travel from lymph nodes to infected tissues

Question 36

\_\_\_ activates lymphocytes

Answer 36

* antigen presentation by dendritic cells, macrophages, or B lymphocytes * leads to clonal selection and expansion

Question 37

lymphocytes have a functionally infinite capacity for \_\_\_

Answer 37

antigen recognition

Question 38

lymphocyte antigen specificty ___ over time

Answer 38

improves

Question 39

\_\_\_ cells preserve the ability to recurrently respond to an antigen

Answer 39

memory T and B cells

Question 40

which cells kill pathogenic self cells and regulate the immune response?

Answer 40

T cells

Question 41

describe how cytotoxic (CD8) T cells kill pathogenic self cells

Answer 41

recognizes complex of viral peptide with MHC class I and kills infected cell

Question 42

describe how regulatory (CD4) T cells kill pathogenic self cells

Answer 42

* Th1 cell recognizes complex of bacterial peptide with MHC class II and activates macrophage * helper T cell recognizes complex of antigenic peptide with MHC class II and activates B cell

Question 43

describe how B cells produce antibodies

Answer 43

* a resting B cell encounters an antigen * the B cell is stimulated and gives rise to antibody-secreting plasma cells * plasma cells secrete antibodies into the blood and tissues

Question 44

antibodies are targeted against a single \_\_\_

Answer 44

antigen

Question 45

what is the normal response and deficient response to an infectious agent?

Answer 45

* normal response - protective immunity * deficient response - recurrent infection

Question 46

what is the normal response and deficient response to an innocuous substance?

Answer 46

* normal response - allergy * deficient response - no response

Question 47

what is the normal response and deficient response to a grafted organ?

Answer 47

* normal response - rejection * deficient response - acceptance

Question 48

what is the normal response and deficient response to a self organ?

Answer 48

* normal response - autoimmunity * deficient response - self tolerance

Question 49

what is the normal response and deficient response to a tumor?

Answer 49

* normal response - tumor immunity * deficient response - cancer