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Flashcards in Self Study 2 Deck (59):
1

what bact causes TB

myobacterium tuberculosis

2

where does myobacterium TB thrive

upper lobe and upper part of lower lobe

3

why does MBTB thrive in certain areas of the lung

they are aerobic bacteria and these areas of the lung have inc o2 content

4

what makes mbtb resistant to destr

outer waxy capsule

5

what does the outer waxy capsule on mbtb allow

to continue prod in dead and calcified lesions

6

what are mbtb capable of

retaining growth

7

how many new tb cases occur a year

8 mill

8

how many people die from tb a year

2 mil

9

how many new cases of tb occured in canada in 2003

1600

10

how many people in canada died from tb in 2003

750

11

who has inc incidence for tb

people living in crowded conditions, foreigners

12

2 forms of tb

m. tuberculosis hominis
m. tuberculosis bovine

13

another name for m. tuberculosis hominis

human tb

14

how is bovine tb acquired

drinking milk from infected cows

15

what part of the body does m. tb bovine affect first

GI tract

16

how does h. tb hominis travel

airborne infc.

17

mechanism of tb m hominis travel

droplets are in air when infected person coughs, sneezes, talks, particles evaporate and are suspended in the air

18

what happens when a tb bacteria is inhaled

travel down bronchial tree and deposit in alveoli

19

what happens to the bacilli once they are deposited in alveoli

alveolar macrophages phacocytose

20

why are bacilli not killed after alveolar macrophages attack them

cell wall blocks the fusion of phagosomes and lysosomes

21

what happens when the fusion of phagosomes and lysosomes is stopped by the bacilli

macrophages initiate cell mediated immune response

22

how are bacilli antigens presented to t lymphocyte

macrophages which have ingested them present them

23

why is lung tissue damaged in TB

lytic enzymes are released by t macrophages

24

why do t macrophages release lytic enzymes

sensitized t lymphocytes stimulate macrophages to produce lytic enzyme

25

Ghon focus

granulomatus legion

26

how do ghon focus' develope

increased cell mediated immune response

27

what does a ghon focus contain

tubercle bacilli, modified macrophages, other immune cells

28

what causes tissue necrosis

when the number of organisms is high, H rxn lt necrosis

29

what lymph nodes do tb bacteria travel down via lympth channels and end up

tracheobronchial lymph nodes

30

what happens when tb bacteria is in tracheobronchial lymph nodes

cheese like granulations form

31

ghon complex

combination of primary lung lesions and lymph node granulomas

32

what happens to a ghon complex over time

heals, but dormant bact may remain

33

what happens if somebody with dormant TB becomes immunocompromised later on

dormant infc can dev into secondary tb

34

primary tb

infc that develops in previously unexposed persons

35

what happens when people with intact immune systems develop a primary infc

supressed infc

36

why is the infc in primary tb supressed

t lymphocytes and macrophages surround organisms and limit spread

37

do people with tb have an active disease

no

38

what happens in primary tb when a pt has compromimsed IR

they dev progressive primary tb with destruction of lung tissue that spreads to multiple sites within the lung

39

miliary tb

rare form of tb that moves into blood vessel causing lesions

40

secondary tb

occurs when pt has laready been exposed to disease

41

what causes secondary tb

reinfection from another inhaled droplet or reactivation of a healed primary lesion

42

what is an aggravating factor for secondary tb

cell mediated H rxn that causes cavities to merge and create one large cavity

43

what can merging of cavities cause

plueral effusion
tb emphysema

44

mnfts primary tb

non spec and insidious
fever
wt loss
fatigue
night sweats

45

what other mnfts may accompany primary tb

pleuritis
lymphadenitis

46

mnfts of secondary tb

low grade fevers
night sweats
fatigue
anorexia
wt loss
dry cough

47

what does disease process of secondary tb do to a dry cough

turns it into a productive cough with purulent or blood tinged sputum

48

what mnfts occur in later secondary tb

dyspnea
orthopnea

49

dx for tb

tuberculin skin tests
cxr
culture

50

what does it mean if a person tests positive for skin tb

they may not have an active form, they have been exposed to baccillus and cell mediated immunity forms

51

what do cxr's show in pts with tb

consolodated lesions (active)
lesions, scars (inactive)

52

goal of tx for tb

eradicating bacteria while not creating drug resistance in pt

53

types of tx for tb

chemo
antimycobacterial tx

54

what drug is used to treat tb in pts >35yo, immunocompromise, peds,

isoniazid

55

what drugs are usually used in tb

INH
rifampin
pyrazinamide
ethambutol
streptomycin

56

how do we avoid drug resistance

use combinations of drugs

57

what vaccine is used in pts who have high risk of dev infc

calmette geurin

58

what does calmette geurin do in skin tests

changes ability to detect dormant tb,

59

where does the calmette geurin vaccine inconsistent

pulmonary tb