13. Lung and the Environment Flashcards

1
Q

a few forces that control particle deposition in the lungs

A
  • inertia/impaction: tendency to fail to turn corners of R tract, impact upon nose, pharynx, bifurcations
  • sedimentation: particles settle acc to their weight
  • diffusion (random movement)
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2
Q

characteristics that modify particle deposition?

A
  • breathing pattern

- anatomy of the resp tract

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3
Q

a few defense mechanisms we have against inhaled substances?

A
  • physical barriers (ie nose filtration)
  • mucociliary clearance
  • alveolar clearance
  • cough
  • immune system
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4
Q

describe mucociliary clearance

A

active from resp bronchiole to larynx. coordinated activity of ciliated epithelium. epit cells covered with a fluid bilayer, with both solution phase and gel phase. sol phase facilitates ciliary beat.

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5
Q

how quickly do most normal people clear inhaled particles from the bronchi?

A

6 hrs

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6
Q

what phase of mucociliary clearance does cystic fibrosis disrupt (sol or gel)?

A

sol

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7
Q

what phase of mucociliary clearance does chronic bronchitis disrupt (sol or gel)?

A

gel

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8
Q

what phase of mucociliary clearance does Kartagener’s syndrome disrupt?

A

cilia

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9
Q

describe alveolar clearance

A

non ciliated regions. particles transported by alveolar macrophages to mucociliary laler of lymphatic system.

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10
Q

what does the ability to cough depend on?

A

the presence of intact upper and lower afferents and reflex efferents, resp muscles, larynx

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11
Q

what are some examples of diseases caused by inspired substances?

A

silicosis, coal worker’s pneumoconiosis, asbestos-related lung disease, farmer’s lung, malt worker’s lung

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12
Q

where does asbestos exposure occur?

A

mining, home insulation, production of fireproof textiles, paints, brake and clutch linings

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13
Q

what usually occurs with inorganic dust diseases (pneumoconiosis)?

A

parenchymal inflammation, fibrosis due to the tissue reactions involved in trying to clear organic dusts

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14
Q

besides interstitial fibrosis, another major lung disease that people exposed to asbestos can present with?

A

cancer. smoking + asbestos exposure together is terrible.

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15
Q

what is organic dust disease? what are the 2 types of immune responses it causes?

A

hypersensitivity.
two types:
-hypersensitivity pneumonitis (ex farmer’s lung)
-occupational asthma (ex cereal worker’s lung)

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16
Q

Features of hypersensitivity pneumonitis?

A

systemic reaction, fever, crackles, restrictive pattern.

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17
Q

Features of occupational asthma?

A

dyspnea/wheezing at work, may have latent period of several hours. cough, sputum may improve weekends and vacations.

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18
Q

what is aspiration?

A

normal people aspirate frequently. clinical meaning of aspiration is inhaling a usually non-respirable particle with subsequent disease

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19
Q

what are 2 mechanisms of aspiration?

A
  • impaired neuromotor function (anesthesia, depressed lungs, alcohol)
  • altered anatomy
20
Q

what is the difference between mainstream and sidestream smoke?

A

mainstream produced when smoker draws on cig. predominant source for smoker.
sidestream = when cig smolders. predominant env source

21
Q

what does nicotine do in the body?

A

binds to acetylcholine receptors at autonomic ganglia, adrenal medulla, NM junction and brain.

22
Q

what are the effects of nicotine in the body?

A

stimulates hormone release: catecholamines, ACTH.
inc heart rate, BP, CO
mental stimulation, relaxation, enhanced learning, memory, attention.
promotes thrombosis, plate agg and vasospasm

23
Q

what % of americans smoke?

A

23%

24
Q

what cancers does smoking contribute to?

A

lung, also oral cav, larynx, esophagus, bladder, kidney, panc, stomach, cervix

25
Q

what cardiac problems are caused by smoking?

A

atherosclerosis, incl coronary artery disease, CV disease, peripheral vasc disease

26
Q

what main resp diseases are caused by smoking?

A

COPD (chron bron, emphy)

27
Q

definition of invol smoking?

A

exposure of non-smokers to tobacco combustion products in the indoor envt

28
Q

chronic effects of invol smoking in children?

A

freq of acute resp illness (asthma, chronic cough, sputum, wheezing) in children 5-20 yo

29
Q

effect of parental smoking on kids asthma?

A

increased incidence

30
Q

smoking cess programs long-term success rate is approx what %?

A

20%

31
Q

4 benefits of smoking cessation

A
  1. inc life expectancy
  2. slowing of progression of tobacco related disease
  3. decr risk of lung cancer
  4. reduction in perioperative resp complications
32
Q

water soluble agents: where do they do damage?

A

they dissolve in upper resp tract. injure immediate air spaces (nose, throat, bronchi).

33
Q

water insoluble agents: where do they do damage?

A

more distal, alveoli, bronchioli

34
Q

water insoluble agents: why delay in recognition?

A

lack of deposition on mucosal surfaces. symptoms delayed 3-30 hrs

35
Q

factors affecting particle deposition

A
  • impaction
  • sedimentation
  • diffusion
36
Q

why do we advise people taking inhalers to inhale slowly?

A

to minimize impaction. also they hold their breath afterwards to allow time for sedimentation (so they don’t exhale the med)

37
Q

what is relevant about Kartagener’s syndrome?

A

structural abnormality of cilia

38
Q

definition of pneumoconiosis?

A

lung disease caused by inhalation of inorganic dusts

39
Q

what is silicosis?

A

one type of pneumoconiosis.

Lung disease secondary to inhalation of silicon dioxide

40
Q

2 types of silicosis?

A

Simple silicosis: generally a radiographic abnormality (nodules), unaccompanied by change in lung function, impairment or disability, or decreased longevity
Progressive massive fibrosis: formation of large, coalescent masses that obliterate lung structure

41
Q

coal worker’s pneumoconiosis: difference from silicosis?

A

only difference is type of dust. CWP may present mosaic. nodules, focal emphysema

42
Q

definition of asbestosis?

A

interstitial lung disease associated with asbestos exposure. may yield a pleural plaque (plates of calcium at lung border on cxr)

43
Q

definition of hypersensitivity pneumonitis?

A

Immunologically mediated lung disease (secondary to inhaled organic dust)
Caused by intense and/or repeated exposure of dusts that reach distal lung units
Same clinical and pathologic findings regardless of organic dust involved
Acute exposure: flu-like symptoms + breathlessness within hours
Chronic exposure: insidious onset of respiratory symptoms, possibly with irreversible fibrosis

44
Q

a few causes of hypersensitivity pneumonitis?

A

Malt worker’s disease
Farmer’s Lung
Tea grower’s disease

45
Q

a few causes of occupational asthma?

A

cereal dust
wood dust
animal proteins

46
Q

what drugs are best to support smoking cessation?

A
  • varenicline
  • Partial agonist for α4β2 nicotinic acetylcholine receptor which may play a role in addiction
  • more successful than buproprion or placebo