Pathology of Obstructive Lung Disease Flashcards
Which three main conditions are obstructive airway diseases?
- emphysema
- chronic bronchitis
- asthma
FEV1 is the…
Forced Expiratory Volume (FEV) of air exiting the lung in the first second of FVC.
FVC is the…
total amount of air expired after taking a maximum inspiration (FVC).
What factors is predicted FVC based on?
age, sex and height
FEV1 is usually about _____ of _____ in healthy persons.
70-80%
FVC
Normal FVC is around ____.
Normal FEV1 is _______.
Therefore, normal FEV1/FVC = ______.
5L
- 5-4L
- 7-0.8
What is a marked fall in PEFR?
<50% of best
What is a moderate fall in PEFR?
50-80% of best
What is a normal PEF in PEFR?
400 – 600 L/min
In obstructive lung disease:
- PEFR is ________.
- FEV1 is _________.
- FVC ________.
- FEV1 _______ of FVC.
- reduced
- reduced
- normal or low
- is less than 70% of
FEV1/FVC < 0.7
Outline the pathogenesis of bronchial asthma.
- mast cell degranulation
- smooth muscle contraction (immediate)
- acute inflammatory response
- chronic inflammation in chronic asthmatics.
When can bronchial asthma become irreversible?
Why?
when it becomes chronic
In lifelong asthmatics – ultimately there may be structural changes in airways (fibrosis, scarring) which are not reversible by pharmacological intervention.
What is the aetiology of COPD?
- SMOKING (tobacco)
- atmospheric pollution
- occupation e.g. dust
What impacts your susceptibility to COPD?
How your metabolism handles the chemicals in cigarettes or pollution.
___________ deficiency is an extremely rare cause of emphysema.
Alpha-1-antitrypsin
Does congenital alpha 1 antitrypsin deficiency cause chronic bronchitis?
no, only emphysema
What is the clinical definition of chronic bronchitis?
Cough productive of sputum most days
in at least:
- 3 consecutive months
- for 2 or more consecutive years
When can chronic bronchitis become complicated? (2)
- mucopurulent sputum (acute infective exacerbation)
- when FEV1 falls
What are the morphological changes in chronic bronchitis in the large airways (bronchi)? (3)
- Mucous gland hyperplasia
- Goblet cell hyperplasia
- Inflammation and fibrosis is a minor component
What are the morphological changes in chronic bronchitis in the small airways (bronchioles)? (2)
- Goblet cells appear (where they should not be)
- Inflammation and fibrosis in long standing disease
Why do we have sputum?
When can it be problematic?
It is a defense mechanism - protection from things being inhaled (smoke, pollution).
It can go overboard and protect too much, goblet cells increase in number, we get inflammation and fibrosis. In more chronic cases, chronic irritation leads to chronic fibrosis.
What is the pathological definition of emphysema?
Increase beyond the normal in the size of airspaces ______ to the ________ bronchiole arising either from ________ or from _________ of their walls and without obvious ________.
distal terminal dilation destruction fibrosis
The acinus – in human lung, 1-2cm across, supplied by 1 _______ bronchiole.
Alveolar walls _________ in emphysema.
terminal
disappear
Emphysema is classified according to where the alveolar tissue is lost.
Define centri-acinar emphysema. (2)
- loss of alveolar tissue around the respiratory bronchioles and the alveolar ducts.
- Outside of the acinus – generally not affected (local).
