Immune System 1 Flashcards
1
Q
Define physical barriers.
A
skin and mucous membranes
2
Q
Define leukocytes.
A
- white blood cells
- wide range of immune responses
3
Q
Define lymphoid tissues.
A
- bone marrow, thymus, spleen, lymph nodes, tonsils
- development and function of leukocytes
4
Q
What makes up the skin?
A
- epidermis
- dermis
- sebaceous glands
5
Q
What are sebaceous glands?
A
- inhibit bacterial growth
- sebum = oil
6
Q
What are mucous membranes?
A
viscous mucus traps foreign matter
7
Q
Name 4 leukocyte phagocytes.
A
- neutrophils
- eosinophils
- monocytes
- dendritic cells
8
Q
What is the most abundant phagocyte in leukocytes?
A
neutrophils
9
Q
What are monocytes in leukocytes?
A
macrophages (in tissue)
10
Q
What do dendritic cells do as phagocytes?
A
activate T cells
11
Q
Phagocytes secrete:
A
cytokines
12
Q
Phagocytes circulate in blood for ______ hours and migrate to tissues for ____ days.
A
- 7-10 hours
- a few days
13
Q
Name 3 non-phagocytes.
A
- basophils
- mast cells
- lymphocytes
14
Q
What are mast cells?
A
- cells of skin and mucosa
- histamine
15
Q
What are the 3 types of lymphocytes?
A
- B cells
- T cells
- NK cells
16
Q
B cells are associated with _____.
A
antibodies
17
Q
When B cells contact antigen, they become _____ cells
A
plasma
18
Q
_____ cell secretes antibodies (immunoglobulins).
A
plasma
19
Q
___ ____ _____ mark invaders for destruction.
A
B cell antibodies
20
Q
T cells directly damage ______ cells.
A
foreign
21
Q
T cells contact _____, _____, or _______ cells.
A
infected, mutant, or transplanted cells
22
Q
T cells develop into ______ T cells that destroy.
A
cytotoxic
23
Q
Describe target cells of T cells.
A
- takes several days
- secretory products form pores in the target cell’s membrane
- lysis
24
Q
Most null cells are:
A
natural killer cells
25
Null cells are important defines against ____ _____.
viral infections
26
What are lymphoid tissues?
central lymphoid tissue = bone marrow + thymus
27
Describe bone marrow.
- hematopoietic stem cells
| - leukocyte development
28
Hematopoietic stem cells are precursors for _______.
all blood cells
29
Leukocytes (except T lymphocytes) fully develop in ____ ____.
bone marrow
30
Thymus is responsible for ____ and _____.
migration and maturity
31
T lymphocytes migrate from _____ to _____.
bone marrow to thymus
32
T lymphocytes reach maturity in _____.
thymus
33
What makes up the peripheral lymphoid tissues?
- spleen
- lymph nodes
- tonsils
- adenoids
- appendix
- Peyer's patches
34
Peripheral lymphoid tissues are collections of ____, _____, and _____.
- B cells
- T cells
- macrophages
35
Peripheral lymphoid tissues trap ______ and _____ _____, and expose them to _____ in high concentrations
- microorganisms and foreign particles
| - leukocytes
36
____ and ____ ___ filter blood and lymph.
spleen and lymph nodes
37
What do tonsils and adenoids do?
trap inhaled particles
38
What do the appendix and Peyer's patches do?
trap ingested particles
39
Name 5 nonspecific defences (innate defences).
- physical barriers
- inflammation
- interferons
- natural killer cells
- complement system
40
Define inflammation.
series of events causing accumulation of proteins, fluid, and phagocytes in an injured or invaded area
41
What are the 5 steps of inflammation?
1. macrophages engulf debris and foreign matter
2. capillaries dilate and become more permeable
3. foreign matter is contained
4. more leukocytes migrate to area
5. leukocytes clear infection
42
Describe the phagocytosis of pathogens.
- proteins on microbes bound by macrophages
- triggers phagocytosis and secretions
- secretory products trigger subsequent steps
43
Describe the steps to dilation and increased permeability in capillaries.
- damaged mast cells secrete histamine
- histamine triggers dilation and increases permeability
- result: increased blood flow and increased movement of proteins and cells to injured tissue
44
Name 4 symptoms of inflammation induced by effects of histamine.
- redness
- heat
- edema
- pain
45
Describe the containment of foreign matter during inflammation.
- mast cells and basophils --> heparin
| - heparin prevents clot formation initially so blood cells can access area
46
_____ ____ eventually form a clot in tissue, which does what?
- clotting factors
| - prevent spread of foreign matter
47
What happens within 1 hour for leukocyte migration and proliferation?
neutrophil migration
48
What happens within 10 hours for leukocyte migration and proliferation?
monocyte migration --> macrophages
49
Describe leukocyte proliferation.
- cytokines travel to bone marrow
- stimulate production of leukocytes
- increase 4-5 times in circulating numbers
50
Describe how cells move from blood to tissue triggered by cytokines.
- margination: move to vasculature wall
- attachment: bind to wall
- diapedesis: move between endothelial cells
51
What is movement in tissue to injury called?
chemotaxis
52
Once foreign particles are present in damaged or invaded tissue, _____ must clear the tissue.
leukocytes
53
Name the 4 steps of phagocytosis.
1. attachment
2. internalization
3. degradation
4. exocytosis
54
Describe the attachment step of phagocytosis.
specific: damaged cells or protein-targeted cells
55
Describe the internalization step of phagocytosis.
- fast
| - phagosome + lysosome --> secondary lysosome
56
Describe the degradation step of phagocytosis.
lysosome enzymes degrade phagocytosed product
57
Describe the exocytosis step of phagocytosis.
elimination of some degradation products
58
The secretion of cytokines is by ______.
phagocytes
59
cytokinesis triggers..?
attachment of foreign particles
60
what are the responses of cytokinesis?
- increased b and t cells
- inflammatory effects
- fever inducer
61
what are interferons?
interfere with virus replication
62
what do interferons do?
- signal neighbouring cells
| - resistance to virus increases
63
what are the other roles of interferons?
- enhances phagocytosis
- increased B cell production
- activates immune cells
64
bone marrow produces and secretes more...?
leukocytes
65
B cells->
antibody production
66
T cells->
cell mediated immunity
67
describe what interferons do?
- RNA invades host cell, using cells replication machinery to reproduce
- viral nucleic acid stimulates host cell to secret interferon-a and interferon-b
- kills host cell
- induces neighbouring cells to resist viral infection
- direct effect on cancer cells (inhibit tutor growth)
68
plasma proteins:
- bind to pathogen
- recruits phagocytes
- histamine secretion
- membrane attack complex (mac) formed
69
complement system:
Plasma proteins that lyse foreign cells, especially bacteria
Part of response to antibodies (specific immunity) in addition to nonspecific response
Approximately 30 proteins participate in the response cascade, resulting in MAC reaching the surface of bacteria
MAC pierces the bacterial membrane, causing lysis
70
complement protein functions:
- form MAC to lyse cell
- chemotaxis
- trigger histamine release form mast cells
71
Humoral immunity:
- B cell meditated
- involves secretion of antibodies by plasma cells
- defend against bacteria, toxins,and viruses in body fluids
72
cell-meditated immunity
- T cell mediated
- involves lysis of cells by cytotoxic T cells
- defend against bacteria and viruses in body cells
- part of reaction to transplants and cancer cells
73
what are the features of specific immune response ?
- specificity
- diversity
- memory
- self tolerance
74
describe specificity
- antigens (antibody generators) confer specificity
- complex proteins and polysaccharides
- part of foreign invaders and tumor cells
- epitopes: recognition site for B and T cells
75
B and T cell specificity?
- antigen receptors recognize certain antigens only
- B cells: membrane antibodies
- T cells: T cell receptors
76
what does specificity mean
Specificity means that a B or T cell can recognize only a few of many antigens
77
what does diversity mean
wide array of responses to a wide-array of antigens
