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Microbio Exam 1 > Tissue Responses to Infection > Flashcards

Flashcards in Tissue Responses to Infection Deck (65):
1

T/F:The response an individual shows to an organism is soley dependent upon the qualities of that organism.

False; depends on features of the host and the organism

2

List the 6 WBCs

-neutrophil
-basophil
-eosinophil
-B lymphocyte
-T lymphocyte
-Monocyte/macrophage

3

White blood cells can be grouped into granulocytes and mononuclear cells. Divide the WBCs into these categories.

-Granulocytes: neutrophil (hypersegmented), eosinophil(bilobed), basophil
-Mononuclear: macrophage/monocyte (kidneyshaped), lymphocytes/plasma cells

4

-itis means

-inflammation

5

T/F: If one sees inflammation, there must be an infection.

False; there are MANY causes of inflammation, and infection is just one of them!

6

5 categories of microbes

1. bacteria
2. viruses
3. fungi
4. parasites: protozoa and helminths
5. prions

7

Where do microbes live: intra or extracellular
1. bacteria
2.viruses
3.parasites
4.fungi
5.prions

1. either
2.intracellular
3. either
4. either
5. intracellular

8

Acute vs. chronic infection

Acute: rapid onset, short duration, "days"
Chronic: slower onset, longer duration, weeks, months,years

*subacute is in between*

9

What are the 6 categories of tissue response to infection?

1. acute inflammation
2. chronic inflammation
3. Granulomatous inflammation (subtype of chronic)
4. Eosinophilia
5. Cytopathic/cytoproliferative changes
6. Tissue necrosis

10

What are the characteristics of inflammation

-rubor (red)
-calor (hot)
-Tumor (swelling)
-Dolor (pain)

11

What organisms cause acute inflammation?

-extracellular/pyogenic bacteria: GPC and GNR
-some extracellular fungi

12

________________________ are the first line of defense against extracellular pathogens.

-neutrophils and macrophages

13

What is pus?

-viable and dying WBCs
-primarily neutrophils, liquified tissue and cellular debris

14

Acute tonsilitis is an example of acute inflammation. What causes it?

-GAS

15

Edema

-excess, protein-rich fluid in the interstitial spaces

16

If you were to microscopically examine exudate (pus), what would you see?

-neutrophils
-macrophages
-protein-rich edemic fluid

17

3 potential outcomes of acute inflammation

1. normal healing (usual outcome!)
2. tissue destruction
3. progression to chronic inflammation

18

2 examples of tissue destruction due to acute infections

-abscess formation
-scarring and fibrosis

19

What organisms are associated with rapid, extensive tissue destruction and abscess formation?

-Staphylococcus
-Klebsiella

20

What is an abscess?

-lesion consisting of a central area of tissue necrosis and neutrophils
-where acute inflammatory response has resulted in local destruction and replacement with a collection of neutrophils (pus)

21

How can you tell if an acute infection and become chronic? What does this signify?

-inflammatory cell infiltrate will change primarily from neutrophils and macrophages to lympocytes, plasma cells, and macrophages
-signifies a switch from innate immunity to adaptive immunity
-acute inflammatory cells may still persist and one may see a mix of inflammation

22

Abscesses with pus are usually due to __________.

-Staphylococcus aureus

23

Bacterial abscesses are most common, but ________ are often seen, especially in immunocompromised hosts with decreased neutrophilic activity.

-fungal abscesses

24

What eventually happens to an abscess that is not resolved?

-becomes surrounded by a rim of blood vessels and fibrous tissue
-fibrosis serves to "wall off" the area of infection and necrosis
-blood vessels in wall serve as ongoing source of neutrophils for abscess

25

What is seen within a chronic abscess?

-neutrophils, macrophages, necrotic tissue

26

If you see an abscess, there are 2 types of organisms that may cause is, what are they?

-bacteria
-fungi

27

Vascular changes associated with acute inflammation

-increased blood flow
-edema

28

What will be the pathology of acute infections due to intracellular microbes?

-see lymphocytic infiltrate as NK cells are first line of defense for extracellular organisms
-early response by NK cells, followed by cell-mediated immune reactions
-NO PUS bc no neutrophils

29

A patient presents with acute infection and microscopy shows a dense lymphocytic infiltrate, what can be ruled out?

-extracellular bacteria/fungi
-this is classic sign of intracellular infection
-usually this is an acute viral infection

30

Chronic inflammation is used to describe the pattern of inflammation seen in tissues in which ___________ predominate.

-mononuclear cells: lymphocytes, macrophages, plasma cells
*note the lymphocyte overlap with acute viral infections

31

What are the potential infection organisms of chronic inflammation?

-viruses (intracellular)
-intracellular bacteria
-intracellular parasites
-spirochetes
-any persistent infection due to any organism

32

On top of the mononuclear and lymphocytic cells involved in chronic inflammation, what else is a mediating factor?

-cytokines

33

Compare acute to chronic inflammation microscopic pathology

Acute: neutrophils, macrophages, edema
Chronic: lymphocytes, plasma cells, macrophages, but primarily lymphocytes

34

Compare microorganism causes of acute and chronic inflammation

-acute: extracellular organisms (bacteria and fungi)
-Chronic: intracellular organisms (viruses, some bacteria and fungi)

35

If a patient presents with a microscopically "chronic"-looking illness, what are the potential causes?

-chronic persistent infection with intracellular organisms or any hard to eradicate organisms
-acute infection with intracellular organisms
**can be acute or chronic**

36

Acute and chronic inflammation may co-exist when?

-in chronic, hard to eradicate infections of any cause

37

What is the hallmark of a granuloma?

-a collection of activate macrophages (epithelioid cells or epithelioid histiocyte" which are large cells with abundant pink cytoplasm

38

Epithelioid cells often fuse to form _______.

-giant cells

39

What may or may not accompany granulomas in a granulomatous inflammation?

- with or without a rim of lymphocytes, fibroblasts
-with or without central necrosis (caseous necrosis)

40

What 2 things are involved in granuloma formation?

-CD4+ T cells
-cell mediated immunity

41

Steps of granuloma formation

-APC present intracellular organism to CD4+ TH1 cell
-T cell is activate and produces cytokines which recruit monocytes/macrophages from circulation to the tissue where they are needed
-macrophages are also activated by these cytokines to increase their phagocytic activity
-on going interactions between T cells and macrophages maintain the granuloma

42

When you identify a granuloma, it indicates what? Main examples?

-that there has been a cell mediated response against a poorly degradable intracellular microbe

43

What organisms elicit granulomatous inflammation?

-intra cellular
-poorly digestible, poorly soluble
-resistant to eradication
-Mycobacterium: TB!!!!!
-Some fungi (Histoplama)
-Some worms (Schistosoma)

44

If you see granulomatous inflammation in the lungs, what should you be thinking?

-TB!!!

45

__________ is a characteristic of TB

-caseous necrosis that accompanies granulomatous inflammation

46

Pathology of granulomatous inflammation

-epithelioid histiocytes (activated macrophages)
-giant cells
-lymphocytes
-plasma cells

47

Clinical presentation of granulomatous inflammation

-chronic infections due to a limited number of organisms (TB!!!!!, some fungi and worms)

48

How to tell an abscess and caseating necrosis apart?

-Microscopically: abscess have neutrophils and pus in it, while caseating necrosis doesnt have cells despite them both have necrosis tissue
-Cultures

49

Eosinophils defend against __________. How?

-helminthic (worm) infections
-IgE abs bind to helminthic parasites and the Fc regions recognized by eosinophils which activates release of granules

50

Why do eosinophils rely moreso on granule release that phagocytosis?

-worms are extracellular organisms and are too large to be ingested
-they are also resistant to most of the phagocytic enzymes and antimicrobial products

51

Eosinophilic granules contain _________. What is good and bad about this compound?

-Major basic protein
-it is toxic to helminths, but also causes extensive host tissue damage

52

When we see eosinophils in the inflammatory infiltrate, we look for _______ as a potential cause.

-worms

53

Granulomas often form in response to foreign materials, and as such may else be present with _______ infections due to eggs.

-worm
**remember granulomas can also signify hard to digest tissues, like foreign objects and eggs or parasites

54

Cytopathic changes are ______ induced. What are some common features?

-virus induced
-nuclear inclusions, cytoplasmic inclusions (both due to viral aggregates) and multinucleated cells due to cell fusion, cell enlargement
-amount of inflammation is variable

55

Viruses can cause observable changes in the morphology of the cells. These changes are called ___________.

-cytopathic effects

56

Cytomegalovirus cytopathic effects

-intranuclear and cytoplasmic inclusions

57

Cytopathic changes see with herpes simplex virus

-multinucleated cells (cell fusion)

58

HPV cytopathic changes

-enlarged nucleus
-binucleated
-perinuclear halo

59

Adenovirus cytopathic changes

-intranuclear inclusion

60

T/F: Not all viruses cause cytopathic changes.

-True; but when they do, they give us insight into their identification

61

Cytoproliferative changes are _____ mediated. What are they a mechanism for?

-virus-mediated
-mechanism to transform cells into benign or malignant cells

62

HPV as an example of benign and malignant cytoproliferative changes

-Benign proliferative=warts; viral proteins free in cytoplasm, NOT DNA
-Cervical cancer: viral proteins integrated into host DNA

63

T/F: HPV infection alone is sufficient for the development of cancer.

-false; many other co-factors must be involved as well

64

Characteristics of tissue necrosis

-tissue damage due to toxins
-little inflammation
-widespread necrosis

65

What can cause tissue necrosis?

-toxin mediated via bacteria, parasites
-viruses