Pathology of obstructive disease Flashcards
What is the FEV1?
Forced Expiratory Volume of air exiting the lung in the first second of breathing out
What is the FVC?
Final Total amount or air expired
What percentage is the FEV1 of the FVC
70-80%
The ratio is FEV1:FVC = 0.7or0.8
What is the normal FEV1 volume in litres?
3.5-4
What is the volume of the FVC in litres?
5
What happens to FEV1 and FVC in obstructive lung disease?
Reduced to less than 70% of the FVC
FVC can be also reduced
PEFR also reduced
What type of hypersensitivity is bronchial asthma?
Type 1
Is bronchial asthma reversible and if yes, how?
Reversible either natrually or by medical intervention
The bronchial smooth muscle contraction and inflammation can be modified by drugs
What is the aetiology of chronic bronchitis and emphysema?
Smoking, atmospheroc pollution and occupation: dust
Effect of age and susceptibility
Whats the clinical definition of chronic bronchitis?
Cough productive of sputum most days
in at least 3 consecutive months
for 2 or more consecutive years
What is complicated chronic bronchitis?
Its when the mucopurulent (acute infective exacerbation) or when FEV1 falls
What are the morphological changes in large airways for chronic bronchitis?
Mucous gland hyperplasia
Goblet cell hyperplasia
Inflammation and fibrosis is a minor component
What are the morphological changes in small airways for chronic bronchitis
Goblet cells appear
Inflammation and fibrosis in long standing disease
What is the pathological definition of emphysema?
Increase beyond the normal in the size of airspaces distal to the terminal bronchiole arising either from dilatation or from destruction of their walls and without obvious fibrosis.
What occurs during centriacinar emphysema?
Begins with bronchiolar dilatation
Then alveolar tissue is lost
What is the most important form of emphysema?
Centriacinar
Caused by smoking
What does panacinar involve?
Involving wiping out of all the lung tissue
What is a bulla?
is an
emphysematous
space
greater than 1cm
Why do people with hyperinflation with emphysema find it easier to breathe?
Small airways are kept open
What does alpha 1 antitrypsin deficiency
Anti-elastase decreases so the elastase and proteases quantity increases and so tissue destruction increases and leads to emphysema
Why does smoking cause emphysema?
Inflammatory cells increase
Anti-elastase enzymes decrease
Repair mechanisms and elastin synthesis decreases
Which mechanism of airway obstruction in COPD can respond to pharmacological intervation?
Smooth muscle tone and inflammation
What is the most important aspect in emphysema?
LOSS OF ALVEOLAR ATTACHMENTS is most important
