Nonspecific Host Defenses Flashcards
Chapter 16 (132 cards)
1
Q
What is Resistance?
A
Ability to prevent disease (aka immunity)
2
Q
What is Susceptibility?
A
Vulnerability to disease
3
Q
What is Innate Resistance (Non-Specific)?
A
Defense mechanism against ANY pathogen
4
Q
What is Adaptive Resistance (Specific)?
A
Define mechanism against SPECIFIC pathogen
5
Q
Examples of Innate Resistance (5):
A
- skin
- mucosa
- phagocytosis
- inflammation
- fever
6
Q
Examples of Adaptive Resistance (2):
A
- cell mediated immunity (CMI)
- humoral immunity
7
Q
What cell is involved in cell mediated immunity?
A
T cells
8
Q
What cells is involved in humoral immunity?
A
B cells and antibodies (Ab)
9
Q
What are the first line of defense? (2)
A
- intact skin
- mucous membranes
10
Q
What are the second line of defense? (4)
A
- phagocytes
- inflammation
- fever
- antimicrobial substances
11
Q
What are the third line of defense?
A
- humoral immunity (bursa maturation)
- cell mediated immunity (thymus maturation)
12
Q
(T/F) The different components of the immune system are mutually exclusive
A
False, they interact with each other
13
Q
Describe Innate Immunity (3)
A
- present at birth
- always present with rapid responses
- no specific recognition/memory
14
Q
What activates Innate Immunity?
A
Toll Like Receptors (TLR) proteins on membranes of defensive cells
15
Q
What do TLR’s attach to?
A
Pathogen Associated Molecular Patterns (PAMP’s): LPS, peptidoglycan, capsule proteins
16
Q
(T/F) Cells release chemicals that regulate the immune response
A
True
17
Q
What type of barriers do Innate Defenses provide? (2)
A
- physical
- mechanical
18
Q
What are examples of physical barriers? (2)
A
- intact skin
- mucous membranes
19
Q
What are examples of mechanical barriers? (6)
A
- tears
- saliva
- mucus
- cilia
- mucus-coated hairs of nose
- flow of urine
20
Q
What are examples of Chemical Factors in Nonspecific Defenses? (7)
A
- sebum
- perspiration
- lysozyme
- gastric juice
- vaginal secretions
- stomach acid
- transferrin
21
Q
Describe sebum and its affects (4):
A
- contains unsaturated fats
- inhibits growth of some bacteria
- keeps pH of skin low
- protective coat over skin
22
Q
What does Perspiration do?
A
Eliminates wastes and flushes microbes
23
Q
What does Lysozyme do?
A
Degrades peptidoglycan layer of Gram (+) bacteria
24
Q
What are examples of Lysozyme? (5)
A
- tears
- saliva
- perspiration
- tissue fluids
- nasal secretions
25
Describe Gastric Juice (2)
- contains HCl (hydrochloric acid)
- pH: 1.2 - 3
26
What does stomach acid do?
Kills most bacteria because of its low pH (some toxins + microbes survive)
27
What does Transferrin do?
Prevents bacteria from using iron in the body
28
How does Normal Flora aid in innate protection? (4)
- prevents overgrowth of pathogens (competition)
- produces substances that kill pathogens (bacteriocins)
- change pH and oxygen
- probiotics
29
Define Bacteriocins
Substances that kill pathogens
30
What does the Second Line of Defense do?
Control pathogens/infections when the first line has failed
31
Describe the Second Line of Defense
(4):
- defensive cells (phagocytes)
- inflammation
- fever
- antimicrobial substances (interferon + complement)
32
What are examples of Antimicrobial Substances? (2)
- interferon
- complement
33
What are the 3 granulocytes?
- neutrophils
- basophils
- eosinophils
34
Describe Neutrophils (3)
- 60-70% of WBCs
- Polymorphonuclear neutrophils (PMNs)
- Can enter tissues (highly phagocytic)
35
Describe Basophils (3)
- 0.5-1.0% of WBCs
- inflammation & allergies, release histamines
- tissue mast cells are similar
36
Describe Eosinophils (3)
- 2-4% of WBCs
- allergies and helminth infections
- may be phagocytic
37
What are the 2 Monocytes/Macrophages?
- Monocyte
- Dendritic Cells
38
Describe Monocytes (4)
- 3-8% of WBCs
- macrophage = mature
monocytes/professional phagocytes
- process antigens (Ag)
- secrete compounds that regulate immune system
39
What elicits an antibody response?
Antigens
40
Describe Dendritic Cells (3)
- derived from monocytes
- skin, mucous membranes, lymph nodes
- destroy by phagocytosis, initiate adaptive response
41
Which cell makes up around 60 - 70% of WBCs?
Neutrophils
42
Which cell makes up around 0.5 - 1.0% of WBCs?
Basophils
43
Which cell makes up around 2 - 4% of WBCs?
Eosinophils
44
Which cell makes up around 3 - 8% of WBCs?
Monocytes/Macrophages
45
Which cell makes up around 20 - 25% of WBCs?
Lymphocytes
46
What are the 3 types of Lymphocytes?
- Natural Killer Cells
- B Lymphocytes
- T Lymphocytes
47
What do Natural Killer Cells do? (2)
- kill infected/tumor cells
- recognize abnormal proteins on surface
48
What do B Lymphocytes do?
Produce Antibodies
49
What do T Lymphocytes do?
Involved in cell mediated immunity
50
What lymphatic tissues do Lymphocytes circulate? (7)
- tonsils
- lymph nodes
- spleen
- thymus gland
- bone marrow
- appendix
- peyer's patches (small intestine)
51
What is Phagocytosis?
Cell ingesting any particulate matter (microbes)
52
What are Phagocytes?
Cells that ingest microbes
53
What type and line of defense are Phagocytes?
- Nonspecific mechanism
- Second Line of Defense
54
What is a Leukocyte?
White Blood Cell (WBC)
55
What are the 5 basic types of WBCs?
- granulocytes (3)
- monocytes
- lymphocytes
56
What is Leukopenia?
Decrease in WBCs
57
What is Leukocytosis?
Increase in WBCs
58
What is a possible cause of Leukopenia? (1)
AIDS
59
What is a possible cause of Leukocytosis? (2)
- Infectious mononucleosis
- Gonorrhea
60
What do Neutrophils, Monocytes, and Dendritic cells do when there's an infection?
Leave circulation -> Enter tissues -> Migrate to infection site
61
Which WBC arrives to the site of infection/injury early in the course of an infection?
Neutrophils (PMNs)
62
What do monocytes do at the site of infection? (2)
- enlarge and mature into macrophages
- become phagocytic
63
Which WBC reaches the area later in the infection process?
Monocytes/Macrophages
64
What is Chemotaxis?
Movement of phagocytes to site of infection due to attraction of released chemicals
65
What releases Chemotaxins? (4)
- basophils
- tissue
- bacteria
- complement
66
What is Adherence?
Phagocyte ATTACHMENT to bacterium
67
How can capsules affect attachment?
Resists attachment
68
What protein prevents attachment?
M protein
69
What facilitates adherence?
Attachment of PAMPs (pathogen associated molecular pattern) to TLRs (toll like receptors)
70
What are Opsonins?
Proteins that promote phagocytosis
71
What is Opsonization?
Promotions of phagocytosis (by Ab + components of the complement system)
72
What is Ingestion?
Engulfment of the bacterium
73
What is the phagocyte plasma membrane that extends in phagocytosis called?
Pseudopods
74
Where is the engulfed bacterium held?
Phagosome
75
What is a Phagosome
Membrane bound vesicle
76
What is Digestion?
Fusion of phagosome with a lysosome
77
What is a Phagolysosome?
Fusion of phagosome with a lysosome
78
What are the two ways bacteria can be killed during digestion?
- anaerobically (hydrolytic or lysosomal enzymes)
- aerobically (toxic oxygen compounds)
79
When bacterium is killed aerobically due to toxic oxygen compounds it is called:
Respiratory Burst
80
What 2 structures inhibit adherence?
- capsules
- protein M
81
What 3 microbes are not killed when ingested?
- Staphylococci
- Trypanosoma
- Mycobacterium, HIV, Plasmodium
82
How do Staphylococci avoid being killed during ingestion?
Secreting leukocidin
83
How do Trypanosoma avoid being killed during ingestion?
Lyse phagocyte membranes
84
How do Mycobacterium, HIV, Plasmodium avoid being killed during ingestion?
Prevent fusion of phagosome and lysosome
85
How do Biofilms evade phagocytosis?
Phagocytes can't detach them from the surface
86
What are the tell-tale signs of inflammation? (4)
- redness
- heat
- pain
- swelling
87
What typically causes inflammation?
Cells and acute phase proteins (complement, fibrinogen, kinins)
88
(T/F) Microbes can initiate inflammation
True
89
(T/F) Inflammation cannot result in loss of function
False
90
What are the functions of inflammation? (3)
- destroys/removes microbes
- limit spread of microbes
- repairs tissues
91
What can enhance inflammation?
Microbial structures (LPS, flagella, DNA) attaching to TLRs = induces acute phase proteins
92
What does the Vasodilation of Blood Vessels mean?
Increased diameter of blood vessels
93
What does Vasodilation of Blood Vessels cause? (2)
- increased blood flow
- redness and heat (at site)
94
What do Mediators do?
Increase permeability in capillaries
95
What is Edema?
Blood cells + fluid entering tissues (swelling)
96
What can cause inflammation?
Chemical mediators released from damaged cells
97
What are 4 examples of chemical mediators?
- histamine
- kinins
- prostaglandins
- leukotrienes
98
What is Margination?
Phagocytes (Monocytes and PMNs) migrate to site & stick to blood vessel walls
99
What is Diapedesis?
Phagocytes move between the endothelial cells of the blood vessel walls
100
What mediates migration of phagocytes into tissues?
Chemotaxins
101
What enters the tissue's first?
PMNs (like neutrophils)
102
What is pus made of?
Dead cells and fluid
103
What is a pyogenic infection?
Any infection that forms pus
104
Blood fluid in tissue is called:
Edema/swelling
105
What is the final stage of inflammation?
Tissue Repair
106
Is inflammation benifical?
Yes, but chronic inflammation can cause permanent changes in tissues
107
What is a fever?
Systemic response to infection
108
What part of the brain causes fevers?
Hypothalamus
109
What causes a fever?
- bacterial endotoxin (exogenous pyrogen)
- IL-1 (endogenous pyrogen)
110
What do shivers and chills do to body temperature?
Raise body temperature
111
What does sweating or crisis do to body temperature?
Lowers body temperature
112
What happens during a fever? (4)
- T lymphocytes activated
- Intensifies Interferons (stops replication of some viruses)
- Decreases iron uptake (some)
- May increase tissue repair
113
What do interferons effect? (1)
Viruses
114
What do Complements effect? (2)
- Bacteria
- Viruses
115
What are examples of Antimicrobial Substances? (4)
- interferons
- complement
- iron binding proteins
- antimicrobial peptides
116
What are Interferons?
Small proteins that interfere with the replication of viruses
117
Who discovered Interferons and when?
Lindenmann & Isaacs, 1957
118
How do interferons act?
Stimulating cells to make AntiViral Proteins (AVPs) -> stops viral replication
119
What are the 3 types of Interferons?
- Alpha-interferon
- Beta-interferon
- Gamma-interferon
120
Which cells produce which interferon?
Every cell can make all 3, but specific cell types produce specific interferons
121
What is considered to be the First Line of Defense for Viral Infections?
Interferons
122
Are interferons specific?
They are HOST specific (not viral)
123
What cells produce alpha-interferons?
B Lymphocytes and Monocytes
124
What cells produce beta-interferons?
Fibroblasts and Epithelial Cells
125
What cells produce gamma-interferons?
T-Cells
126
How many proteins make up the Complement System?
30
127
Where are the proteins in the Complement System found?
In fluid portion of the blood (serum)
128
How are individual proteins of the Complement System activated?
By the presence of foreign cells (bacteria, virus)
129
What is the Nonspecific mechanism for removing foreign cells?
The Complement System
130
Define Cascade in reference to the Complement System?
First activated protein causes a domino affect where the protein next to it is activated (and so on)
131
What are the three pathways of the Complement System?
- classical pathway
- alternative pathway
- lectin pathway
132
Complements destroy microbes by (3):
- cytolysis
- inflammation
- phagocytosis
