Pathology of obstructive lung disease

Question 1

What are the three main obstructive airway diseases ?

Answer 1

Asthma
Chronic bronchitis (COPD)
Emphysema (COPD)

Question 2

What are the normal values for FEV1, FVC and the ratio between them ?

Answer 2

Normal FEV1 - 3.5-4L
Normal FVC - 5L
Ratio FEV1:FVC - 0.7-0.8

Question 3

What is used to predict FVC ?

Answer 3

Age
Sex
Height

Question 4

Besides FEV1/FVC ratio, how else can an obstructive lung disease be demonstrated ?

Answer 4

Peak expiratory flow rate (PEFR)

Question 5

What are the normal values for PEFR ?

Answer 5

Normal 400 – 600 litres/min

Normal range is 80-100% of best value

Question 6

What is PEFR moderate fall ?

Answer 6

50-80% of best

Question 7

What is PEFR marked fall ?

Answer 7

<50-80% of best

Question 8

What is FEV1, FVC, and PEFR in obstructive lung diseases ?

Answer 8

Airflow limitation
PEFR is reduced
FEV1 is reduced
FVC may be reduced
FEV1 is less than 70% of FVC

Question 9

What type of hypersensitivity is bronchial asthma ?

Answer 9

Type 1 hypersensitivity in the airways

Question 10

What causes the decrease in diameter size in bronchial asthma ?

Answer 10

Degranulation of mast cells and smooth muscle contraction

Question 11

What physical substances obstruct airways in chronic asthma ?

Answer 11

Oedema
Mucus
Plasma exudation

Question 12

What can ease bronchial constriction ?

Answer 12

Use of drugs, or spontaneously

Question 13

What is COPD ?

Answer 13

Chronic and irreversible small airway obstruction

Question 14

What is chronic bronchitis ?

Answer 14

Chronic and irreversible small airway obstruction with mucus production and inflammation

Question 15

What is emphysema ?

Answer 15

Chronic and irreversible small airway obstruction with permenant enlargement of air spaces distal to terminal bronchiole and alveolar wall destruction

Question 16

What is the aetiologies of COPD ?

Answer 16

SMOKING
Atmospheric pollution
Occupational- dust

Question 17

What is a rare cause of emphysema ?

Answer 17

Alpha-1-antiprotease deficiency

Question 18

What is the mechanisms of obstruction in large airways in COPD ?

Answer 18

Little contribution by glands and mucous

Question 18

What is the mechanisms of obstruction in small airways in COPD ?

Answer 18

Smooth muscle tone
Inflammation
Fibrosis
Partial collapse of airway wall on expiration

In emphysema- loss of alveolar attachments

Question 19

What portion of COPD is reversible ?

Answer 19

Smooth muscle tone
Inflammation

Respond to pharmacological intervention

Question 20

What is chronic bronchitis defined as clinically ?

Answer 20

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

Question 21

What is complicated chronic bronchitis ?

Answer 21

When sputum turns mucopurulent (acute infective exacerbation)
FEV1 falls

Question 22

What does chronic bronchitis exclude ?

Answer 22

TB
Bronchiectasis
These may be confused with asthma

Question 23

What are the morphological changes in the large airways in COPD ?

Answer 23

Mucous glands hyperplasia
Goblet cell hyperplasia
Inflammation and fibrosis- minor component

Question 24

What are the morphological changes in the small airways in COPD ?

Answer 24

Goblet cells appear | Inflammation and fibrosis in long standing disease

Question 25

What is the pathological definition of emphysema ?

Answer 25

Increase beyond the normal in the size of airspaces distal to the terminal bronchiole arising from wither dilation or from destruction of their walls without obvious fibrosis Loss in alveolar tissue, more space between alveoli.

Question 26

What is an acinus ?

Answer 26

A region of the lung supplied with air from one of the terminal bronchioles

Question 27

What is centiacinar emphysema ?

Answer 27

Loss of lung tissue is concentrated at middle of acinus Then alveolar tissue is lost Predominates in the upper part of the lungs

Question 28

What is panacinar emphysema ?

Answer 28

Emphysema affecting all parts of the secondary pulmonary lobule, typically involving the inferior part of the lung and often associated with a α1-antitrypsin deficiency

Question 29

What is periacinar emphysema ?

Answer 29

Tissue loss around edges of acinus

Question 30

What is a bulla ?

Answer 30

Emphysematous space greater than 1cm

Question 31

What is a bleb ?

Answer 31

A bulla just underneath the pleura

Question 32

What is the pathogenesis of emphysema ?

Answer 32

Smoking (protease-antiprotease imbalance) Ageing Alpha-1-antitrypsin deficiency

Question 33

Why is there hypoxaemia in COPD ?

Answer 33

Airway obstruction Reduced respiratory drive Loss of alveolar surface area Shunt- only during severe acute infective exacerbation

Question 34

What causes physiological pulmonary vasoconstriction ?

Answer 34

When alveolar oxygen tension falls

Question 35

How is Physiological pulmonary arteriolar vasoconstriction protective ?

Answer 35

Do not send blood to alveoli short of oxygen

Question 36

What is Cor pulmonale ?

Answer 36

Hypertrophy of the RV resulting from disease affecting the function or structure of the lung Except where pulmonary alterations are the result of diseases primarily affecting the left side of the heart or congenital heart disease

Question 37

What causes pulmonary hypertension ?

Answer 37

Pulmonary vasoconstriction Pulmonary arterioles- muscle hypertrophy and intimal fibrosis Loss of capillary bed Secondary polycythaemia Bronchopulmonary arterial anastomoses