pathology of obstructive lung diseases

Question 1

3 main diseases that lie under the umbrella of obstructive airway diseases

Answer 1

chronic bronchitis
emphysema
asthma

despite them all causing airway obstruction= the mechanism for the obstruction is different for each one

Question 2

what diseases are not primarily obstructive airway diseases despite causing obstruction with large airways

Answer 2

lung cancer + other tumours
inhaled foreign bodies
bronchiectasis
secondary tuberculosis

Question 3

what is chronic bronchitis and emphysema better known as

Answer 3

chronic obstructive pulmonary disease COPD

Question 4

FEV1 is usually about ___% of FVC

Answer 4

70-80%

Question 5

what are you likely to find in someone with obstructive lung disease?

Answer 5

airflow limitation
peak expiratory flow rate (PEFR) is reduced
FEV1 is reduced
FVC may be reduced
FEV1 is less than 70% of FVC

Question 6

what is PEFR

Answer 6

the max airflow achieved at the beginning of FVC so max air you can inhale basically

Question 7

bronchial asthma

Answer 7

generally considered to be reversible airways obstruction either spontaneously or with medication

Question 8

cause of chronic bronchitis and emphysema ie COPD

Answer 8

smoking
atmospheric pollution
occupation: dust

Question 9

what is the clinical defintion of chronic bronchitis

Answer 9

Cough productive of sputum most days
in at least 3 consecutive months
for 2 or more consecutive years

Question 10

when does diagnosing chronic bronchitis become compliacated

Answer 10

when pus is found in sputum or FEV1 falls

Question 11

what happens in large and small airways in chronic bronchitis

Answer 11

LARGE

• mucous gland hyperplasia
• goblet cell hyperplasia
• inflammation and fibrosis- minor component

SMALL

• goblet cells appear
• inflammation and fibrosis in long standing disease

Question 12

emphysema defintion

Answer 12

Increase beyond the normal in the size of air spaces

loss of alveolar attachments
meaning surface area of lungs reduces and therefore the amount of O2 reaching the lungs also decreases

Question 13

forms of emphysema

Answer 13

centriacinar
panacinar
periacinar

Question 14

centriacinar emphysema

Answer 14

starts with bronchiolar dilatation then alveolar tissue is lost. Mainly bronchiole

Question 15

panacinar

Answer 15

airspaces around about are enlarged - more alveolar duct destruction

Question 16

pathogenesis of emphysema

Answer 16

smoking
protease antiprotease imbalance
ageing
alpha-1-antitrypsin deficiency

Question 17

what happens in large and small airways in COPD

Answer 17

LARGE
little contribution by glands and mucous

SMALL
smooth muscle tone
inflammation
fibrosis 
partial collapse of airway wall on expiration

Question 18

what 2 mechanisms of obstruction respond to pharmacological intervention?

Answer 18

smooth muscle tone

inflammation

Question 19

why is there low levels of O2 in the blood in people with COPD

Answer 19

due to:-
airway obstruction 
reduced respiratory drive - due to high arterial CO2 levels
loss of alveolar surface area 
only during acute infective exacerbation