Part 5: Overview of Innate Immunity Flashcards Preview

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Flashcards in Part 5: Overview of Innate Immunity Deck (89)
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1
Q

Innate resistance protects against

A

Most infectious disease

2
Q

Innate resistance

A
  • Exists at birth and always present
  • Natural host resistance
  • Can be specific for tissues
3
Q

Parts of innate resistance

A

Chemical + physical barriers, special immune system cells, physiological processes and molecular defenses

4
Q

Natural host resistance

A

Susceptability to pathogens varies from species to species

5
Q

Example of natural host resistance

A

Anthrax: fatal blood infection in cattle vs. cutaneous in humans

6
Q

Infection site and tissue specificity

A

Pathogens prefer a specific body site to initiate infection

7
Q

Skin prevents

A

Invasion by microbes

8
Q

Protective protein of skin

A

Keratin

9
Q

pH of skin

A

Slightly acidic pH 5

10
Q

High [NaCl} in skin means

A

Periodic drying

11
Q

Mucous traps

A

Microbes

12
Q

Mucous contains

A

Antimicrobial secretions

13
Q

Example of mucous membrane secretions

A

Lysozyme and defensins

14
Q

Lysozyme does what?

A

Cuts beta-1,4 glycosidic bonds in peptidoglycan

15
Q

Defensin mechanism

A

Antimicrobial peptides that poke holes in bacterial cell membranes

16
Q

The mucocilliary escalator

A

Cilliated cells line the mucous membranes of the airways

Sweeping action moves mucous and microbes away from the lungs

17
Q

Stomach acidity

A

pH ~2
Proteolytic enzymes
Destroys most microbes

18
Q

Small intestine

A

Rapid change in pH
Pancreatic enzymes
Bile
Destroy microbes

19
Q

Large intestine: normal microbiota

A

Microbes that already reside and on the human body

20
Q

Large intestine: normal microbiota action

A

Take up attachment sites, limit available nutrients, make antimicrobial compounds

21
Q

Genitourinary tract protection

A

Urine, flushing action, normal microbiota

22
Q

Vaginal epithelial cells produce

A

Glycogen

23
Q

Lactobacillus acidophilus ferments

A

Glucose to lactose acid

24
Q

Lymphatic system

A

Collection of tissues that bring specialized cells (lymphocytes) into contact with foreign material (antigens)

25
Q

Lymphatic system is made of

A

Lymph vessels and lymphoid organs

26
Q

Lymph

A

Similar to blood containing white blood cells (leukocytes) but without red blood cells

27
Q

Primary lymphoid organs

A

Bone marrow and thymus

28
Q

What happens in bone marrow and thymus?

A

Leukocytes are produced and mature

29
Q

Secondary lymphoid organs

A

Lymph nodes, spleen, MALT

30
Q

Secondary lymphoid organs contain

A

Leukocytes arranged to filter out microbes and antigens

31
Q

Mucosa associated lymphoid tissue action

A

Leukocytes constantly sample their surroundings by phagocytosis looking for foreign material

32
Q

Leukocytes

A

Cells that circulate in the blood and lymph, and reside in lymphoid organs

33
Q

Leukocytes are involved in

A

Both branches of the immune response (innate and adaptive)

34
Q

Granulocytes

A

Cytoplasm contains granules filled with reactive chemicals that can kill microbes and signal other components of immunity

35
Q

Types of granulocytes

A

Basophils and mast cells
Eosinophils
Neutrophils

36
Q

Basophils and mast cells granules stain with

A

Basic dyes

37
Q

Basophils and mast cells are

A

Non-phagocytic

38
Q

Basophil and mast cell location

A

Circulate in blood (basophils) or reside in mucosal tissue (mast cells)

39
Q

Basophils and mast cells can be triggered to

A

Degranulate

40
Q

Basophils and mast cells release

A

Vasoactive mediators

41
Q

Vasoactive mediators

A

Trigger inflamation

42
Q

Type of vasoactive mediator

A

Histamine - involved in the allergic response

43
Q

Eosinophils granules stain with

A

Acidic dyes

44
Q

Eosinophils are

A

Non-phagocytic

45
Q

Eosinophil location

A

Can leave the blood and enter tissues in areas of inflammation

46
Q

Eosinophils attack

A

Large parasites - protozoa and parasitic worms

47
Q

Eosinophils release

A

Reactive oxygen intermediates that destroy parasite from the outside

48
Q

Oxygen intermediates

A

O2-, H2O2, OH

49
Q

Neutrophils

A

Granules are filled with digestive enzymes

50
Q

Digestive enzymes

A

Lysozyme and defensins

51
Q

Neutrophil locations

A

Circulate in blood and migrate to infection sites

52
Q

Neutrophils action

A

Highly phagocytic - “eat” invading bacteria

53
Q

Central component of innate immunity

A

Neutrophils

54
Q

Monocytes location

A

Circulate in the blood, and then migrate to tissues, and differentiate into macrophages and dendritic cells

55
Q

Monocyte mechanism

A

Strongly phagocytic cells involved in antigen presentation

56
Q

Macrophages location

A

Reside in tissues - lungs, liver, spleen, connective tissues

57
Q

Macrophages have

A

Specific surface molecules that recognize pathogens - toll-like receptors

58
Q

Toll-like receptors are found on

A

LPS, peptidoglycan, fungal cell walls that induces phagocytosis

59
Q

Dendritic cell location

A

Reside in tissues that serve as common entry points for pathogens: skin (langerhan’s cells) and mucous membranes of the nose, lungs, and intestines

60
Q

Dendritic cells sample their surroundings using

A

Phagocytosis

61
Q

Dendritic cell action

A

Migrate to lymphoid organs then present foreign antigens on their surface to B and T lymphocytes - trigger the specific (adaptive) immune response

62
Q

Lymphocytes are

A

Specialized leukocytes involved primarily in the adaptive immune response

63
Q

Lymphocyte location

A

Circulate through the blood and reside in lymphoid organs

64
Q

B lymphocytes

A

Antibody producing cells

65
Q

B lymphocytes are involved in

A

Humoral immune response

66
Q

T lymphocytes are involved in

A

Cell mediated immune response

67
Q

Natural killer cells destroy

A

Abnormal cells: cancer cells, cells infected by bacteria or viruses

68
Q

Innate immunity has the ability

A

To destroy a pathogen that has never been encountered before

69
Q

Innate immunity involves

A

Phagocytic leukocytes (neutrophils and macrophages)

70
Q

Phagocytic leukocytes can recognize

A

Pathogen-associated molecular patterns (PAMPs)

71
Q

Pathogen-associated molecular patterns are found on

A

Lipopolysaccharide
Lipoteichoic acid
Flagellin

72
Q

What do we find on phagocytes?

A

Toll-like receptors

73
Q

Toll-like receptors on phagocytes do what

A

Interact with a PAMP

Triggers phagocytosis

74
Q

Phagocytes engulf by

A

Cell membrane invaginates around a foreign particle and engulfs it into a phagosome

75
Q

Phagolysosome

A

A phagosome fused with a lysosome

76
Q

Phagolysosome is filled with

A

Lysozyme and defensins
Proteases
Lipases
Nuclease

77
Q

Proteases

A

Degrade proteins

78
Q

Lipases

A

Degrade phospholipids

79
Q

Nuclease

A

Degrade nucleic acids

80
Q

Oxygen dependent killing

A

Activated phagocytes produce reactive oxygen compounds that kill ingested microbes by oxidizing cell components

81
Q

Oxygen compounds

A

H2O2, O2-, OH-, HOCl, NO

82
Q

Once invaders have been killed in oxygen dependent killing…

A

Neutrophils perform exocytosis - fragments are expelled from the cell
Macrophages and dendritic cells become antigen presenting cells

83
Q

Antigen presenting cells

A

Fragments of the intruder are presented on the cell surface to trigger an adaptive immune response

84
Q

Inflammation

A

General, non-specific reaction to pathogens, toxins, or tissue damage

85
Q

Five cardinal signs of inflammation

A

Redness, warmth, pain, swelling, and loss of function

86
Q

In response to infection, injured tissue and leukocytes release

A

Proinflammatory cytokines

87
Q

Proinflammatory cytokines cause

A

Blood vessels to dilate - brings more leukocytes to the area

88
Q

Extravasation

A

Allows leukocytes to squeeze into tissues and attack invading pathogens

89
Q

Blood leaking into tissue spaces prevents

A

Movement of pathogens by clotting