obstructive diseases 2

Question 1

emphysema pathogenesis

Answer 1

alveolar wall destruction
occurs due to
- repeated damage to alveolar acini
- chronic inflammation - triggered by inhaled particles and cell damage
- imbalance of protease/anti-protease activity
- protease in neutrophils and Mac prophages in lung
- anti-proteases found in bronchial mucus

Question 2

smoking as a cause of emphysema

Answer 2

exposure causes accumulation of neutrophils and macrophages in respiratory bronchioles
inhibits a1-antitrypsin and other anti-proteases
results in inflammation and protease activity

Question 3

genetics as a cause of emphysema

Answer 3

most common is a1-antitrypsin deficiency

Question 4

homozygous genetic a1 antitrypsin deficiency

Answer 4

10% of normal level
cirrhosis of liver in infancy
because a1-antitrypsin is produced here and can’t be transported out
severe emphysema in early adult life

Question 5

heterozygous genetic a1-antitrypsin deficiency

Answer 5

60% of normal level

may be asymptomatic but develop emphysema much earlier if exposed to environmental pollutants

Question 6

symptoms of emphysema occur once

Answer 6

1/3 tissue of the lung is infected

Question 7

emphysema clinical presentations

Answer 7

barrel chest - expiratory difficulty 
decreased exercise tolerance 
wheezing
cough If associated chronic bronchitis 
chest hyper resonant to percussion 
decreased density of lungs on x ray

Question 8

2 types of emphysema

Answer 8

centriacinar

panacinar

Question 9

canrtiaciner emphysema

Answer 9

upper lobes
loss of respiratory bronchioles in the proximal portion of the acinus
usually seen in smokers
more common than panacinar

Question 10

panacinar emphysema

Answer 10

typical of a1-antitrypsin deficiency

all lung fields

Question 11

2 minor types of emphysema

Answer 11

distal acinar

irregular

Question 12

distal acinar

Answer 12

least common form
sub pleural and paraseptal
often forms bullae (bubbles)

Question 13

irregular emphysema

Answer 13

acinus is irregularly involved

associated with scarring, usually clinically insignificant

Question 14

bullae

Answer 14

blisters - where many damaged acini merge and trap air

can rupture and cause spontaneous pneumothorax

Question 15

anthracosis

Answer 15

carbon pigment from smoking, air pollution

Question 16

microscopic pathology of emphysema

Answer 16

damage to alveolar spaces

larger alveolar spaces

Question 17

chronic bronchitis as a clinical diagnosis

Answer 17

cough productive of sputum on most days for three months of the year for at least 2 consecutive years
approx 75 ml of sputum/day

Question 18

symptoms and signs of CB

Answer 18

dyspnoea, eventually respiratory failure with hypoxaemia, hypercapnia and cyanosis

Question 19

CB caused by

Answer 19

chronic irritation - smoking/pollution

Question 20

chronic bronchitis vs bronchiolitis

Answer 20

inflammation of bronchi vs bronchioles

Question 21

complications of chronic bronchitis

Answer 21

acute infective episodes with pneumonia or exacerbation or respiratory failure
cor pulmonale and right heart failure
squamous metaplasia - possibly lead to dysplasia/ malignant change in bronchial epithelium
secondary fibrosis of bronchial lumen

Question 22

CB pathology

Answer 22

inflammation
increased mucus without eosinophils
plugging of bronchi in acute exacerbations
squamous metaplasia

Question 23

bronchiectasis

Answer 23

parmanent and abnormal dilatation of the bronchi and bronchioles as a result of bronchial obstruction or infection or both

Question 24

dilated bronchi

Answer 24

leads to mucus pooling
persistent cough with foul smelling sputum
if localised, surgery may be curative

Question 25

causes of bronchiectasis

Answer 25

tumour or foreign body obstructing bronchi
infection
congenital disorders
- cystic fibrosis, mucoviscidossis, kartgegener’s syndrome, defect in development of bronchi