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Flashcards in Introduction to the Immune System Deck (63):
1

The ___ system is a disparate set of organs and tissues that interact to protect the body from foreign pathogens and dysfunctional self cells.

immune

*disparate = doesn't have single location

2

what is a pathogen?

an organism that has the potential to cause disease

3

what are the 5 classes of pathogens?

  • bacteria
  • viruses
  • fungi
  • protozoa
  • parasites

4

what are the 5 roles of the immune system?

  • kill or control pathogens
  • control disease
  • repair tissue damage
  • organ development
  • maintain organ integrity and function

5

___ was the first practice to provide immunity

variolation

6

what are some examples of variolation?

  • powdered smallpox tissue inhaled or rubbed into scratches on the skin
  • widely practiced in 16th century China
  • introduced to britain by lady montagu in 1721

7

describe vaccination

  • developed by edward jenner in 1796
  • cowpox exposure prevented smallpox
  • substantially safer than variolation/inoculation

8

vaccination was not expanded until louis pasteur and emile roux developed a ___ vaccine in 1865

rabies

9

the study of immunology demonstrated that our body has a responsive system for ___ and ___ pathogens that cause disease

targeting and eliminating

10

what are the most successful developments in public health to date?

vaccines

11

what are the 2 main physical barriers that the body is protected by?

skin and mucosal surfaces

12

name some examples of mucosal surfaces that provide physical barriers for the body 

  • respiratory tract
    • sinuses
    • trachea
    • lungs
  • urogenital tract
    • kidneys
    • bladder
    • vagina
  • gastrointestinal tract
    • oral cavity
    • esophagus
    • stomach
    • intestines
  • mammary glands

13

what properties do protective physical barriers provide for the body?

  • endogenous antimicrobial properties
    • sebum
    • low pH
    • commensal organisms

14

how does the immune system respond when barriers are compromised?

15

describe how the immune system destroys pathogens

16

what are 3 common effector mechanisms utilized in the destruction of pathogens by the immune system?

  1. phagocytosis
  2. granule release
  3. targeted cell death

17

what are the 2 branches of the immune system?

innate immunity and adaptive immunity

18

describe innate immunity

  • rapid response (hours)
  • fixed response
  • limited pathogen specificity
  • consistent response

19

compare primary and secondary responses of the innate and adaptive immune systems

20

describe adaptive immunity

  • slow response (days to weeks)
  • flexible response
  • very selective pathogen specificity
  • response improves with exposure
  • retains a memory of previous infection

21

how do the two branches of the immune system work together?

the adaptive immune system requires an innate response

22

what happens to the number of microorganisms and duration of infection when innate immunity is lacking? what about when adaptive immunity is lacking?

23

what are the principal components of innate immunity?

  • epithelial barriers
  • phagocytes
  • dendritic cells
  • complement
  • NK cells

24

what are the principal components of adaptive immunity?

  • B lymphocytes → antibodies
  • T lymphocytes → effector T cells

25

immune cells function through ___ and ___ interaction

direct and indirect

26

describe direct interaction of immune cells

  • phagocytosis
    • pathogen internalization and destruction
  • immune synapse
    • T cell mediated killing

27

what 4 main components are involved in indirect interaction of immune cells?

  • cytokines
  • chemokines
  • cytotoxins
  • antibodies

28

describe how cytokines function in indirect interaction

  • molecules that activate and regulate immune function through cell-surface receptors
    • inflammatory: IL-1, IL-6, IL-8, TNF-alpha
    • inhibitory: IL-4, IL-10, IL-6, TGF-alpha

29

describe how chemokines function in indirect interaction

  • molecules that attract immune cells to a region of the body
    • C, CC, CXC, CXXC families

30

describe how cytotoxins function in indirect interaction

  • molecules that interact with cells and pathogens to kill them
    • perforin
    • granzyme
    • TNF-alpha

31

describe how antibodies function in indirect interaction

  • proteins targeted against specific pathogens to neutralize, remove, or kill

32

describe leukocyte blood distribution

  • neutrophils: 40-75%
  • eosinophils: 1-6%
  • basophils: <1%
  • monocytes: 2-10%
  • lymphocytes: 20-50%

33

hematopoeitic stem cells make up the precursors for the adaptive and innate immune systems. What are the precursors for each?

  • adaptive immune system
    • common lymphoid precursor
  • innate immune system
    • common myeloid precursor

34

which innate immune cells are the "first responders"?

neutrophils

  • large reserves are stored in the bone marrow and are released when needed to fight infection
  • they travel and enter the infected tissue, where they engulf and kill bacteria/microorganisms
  • they then die in the tissue and are engulfed and degraded by macrophages

35

what are the antigen presenting cells of the innate immune system?

  • monocytes
    • dendritic cells
    • macrophages

36

describe how macrophages kill by phagocytosis and promote inflammation

  • binding of bacteria to phagocytic receptors on macrophages induces their engulfment and degradation
  • binding of bacterial components to signaling receptors on macrophages induces the synthesis of inflammatory cytokines

37

which 3 cells of the innate immune system serve in parasite control?

  • mast cells
  • basophils
  • eosinophils

38

how do mast cells protect against parasites?

  • antimicrobial filled granules (granulocyte)
  • release immune mediators
  • prominent at tissue boundaries

39

how do basophils protect against parasites?

  • granulocyte
  • target parasites
  • increidbly rare; not well understood
  • Fc receptors bind antibodies

40

how do eosinophils protect against parasites?

  • granulocyte
  • target helminth worms and intestinal parasites
  • Fc receptors bind antibodies

41

what are the targeted killer cells of the adaptive immune system?

  • T cells
    • Th helper cell
    • Tc cytotoxic T cell
  • B cells
    • plasma cell
  • natural killer (NK) cells

42

___ drives B cell and T cell pathogen specificity

clonal expansion

43

describe clonal expansion that drives B cell and T cell pathogen specificity

  • Fc receptors bind antibodies
  • MHC class I and II stimulate T cell receptors
  • nearly infinite targeting of pathogens

44

describe the basic anatomy of surface immunoglobulin or B-cell receptors, antibodies, and T-cell receptors

  • Fc receptors bind antibodies
  • MHC class I and II stimulate T cell receptors
  • nearly infinite targeting of pathogens

45

describe the lineages of the innate and adaptive immune system cells starting with hematopoeitic stem cells

46

what are the 2 adaptive immunity responses?

  • humoral
    • antibody mediated
  • cellular
    • mediated by cell-cell interactions

47

describe the humoral and cellular responses of the adaptive immune system

48

describe how antibodies mediate humoral responses

49

which 5 antibody classes are involved with mediating humoral responses in the adaptive immune system?

  • IgG - most abundant antibody
  • IgM - first antibody produced and released
  • IgA - secreted from mucosal glands
  • IgD - B cell surface antibody
  • IgE - basophil and mast cell surface antibody

50

describe how T cells resolve pathogens through direct killing and immune support

51

describe the 2 classes of T cells involved in resolving pathogens through direct killing and immune support

  • cytotoxic (CD8) T cells
    • kill latered self cells
  • helper (CD4) T cells
    • support the functions of the immune system and other organ systems
    • several subtypes
    • regulatory function

52

immune cells develop at and respond from ___ organs

lymphoid

53

describe primary lymphoid organs

  • where immune cells develop
    • bone marrow
    • thymus

54

describe secondary lymphoid organs

  • where adaptive responses initiate
    • lymphoid system
    • spleen
    • mucosa-associated lymphoid tissue (MALT)

55

what important immunity activity occurs in the bone marrow?

myeloid propagation and B cell maturation

*T cells are produced in the bone marrow but migrate to the thymus for maturation

56

what important immunity activity occurs in the thymus?

T cell maturation

*T cells are produced in the bone marrow but migrate to the thymus for maturation

57

describe the lymphatic system

  • collection of extracellular fluid
  • system of lymphatic capillaries and lymph nodes make up the lymphatics that return lymphocytes and lymph to the blood
  • they are regional/localized which is helpful for reactions

58

describe the role of the spleen as a lymphoid organ

  • filters blood borne antigens

59

describe the role of mucosal tissues as lymphoid organs

  • points of pathogen susceptibility
  • function like lymph nodes in the absence of a lymphatic system
  • MALT (think of peyer's patches)

60

describe the generalized immediate innate immune response to infection

0-4 hours

61

describe the generalized induced innate immune response to infection

4 hours to 4 days

62

describe the generalized adaptive immune response to infection

4 days until defeat of the pathogen, defeat of the host, or the truce of chronic disease

63

what are the 9 steps in the basic process of pathogen resolution?

  1. injury/pathogen infiltraiton
  2. resident immune cells respond
  3. inflammatory response
  4. innate pathogen targeting
  5. pathogenic antigens presented in the lymph nodes
  6. adaptive immunity initiated
  7. ongoing immune response
  8. pathogen destroyed or sequestered
  9. memory cells formed