Pathology of Obstructive Lung Disease

Question 1

What is the normal value for FEV1?

Answer 1

3.5-4 litres

Question 2

What is the normal value for FVC?

Answer 2

5 litres

Question 3

What is the normal ratio for FEV1:FVC?

Answer 3

0.7-0.8

Question 4

What % is FEV1 of FVC?

Answer 4

70-80%

Question 5

Which factors may influence FEV1 and FVC?

Answer 5

Age, height and sex

Question 6

What is the average peak rate of flow? (PEFR peak expiratory flow rate)

Answer 6

400-600 litres/min

Question 7

Describe the values of PEFR, FEV1, FVC in those with obstructive lung disease.

Answer 7

Peak Expiratory Flow Rate (PEFR) is reduced
FEV1 is REDUCED
FVC may be reduced
FEV1 is less than 70% of FVC

Question 8

What is the most common cause of chronic bronchitis and emphysema (COPD)?

Answer 8

Smoking :)

Question 9

Which extremely rare deviancy can lead to emphysema alone?

Answer 9

Alpha-1-antiprotease (antitrypsin) deficiency

Question 10

Do individuals usually only have emphysema or chronic bronchitis or do they more often have both?

Answer 10

Both

Question 11

What is the clinical definition of chronic bronchitis?

Answer 11

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

Question 12

What may chronic bronchitis be confused with clinically?

Answer 12

Chronic bronchial asthma

Question 13

When does complicated chronic bronchitis happen?

Answer 13

When sputum turns mucopurulent (acute infective exacerbation) or FEV1 falls

Question 14

What are some of the morphological changes in the large airways of those with chronic bronchitis?

Answer 14

Mucous gland hyperplasia
Goblet cell hyperplasia (increased in number)
Inflammation and fibrosis is a minor component

Question 15

What are some of the morphological changes in the small airways of those with chronic bronchitis?

Answer 15

Goblet cells appear
Inflammation and fibrosis in long standing disease

Question 16

What is the pathological definition of emphysema?

Answer 16

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.

Question 17

What is the most common form of emyphesma?

Answer 17

Centriacinar emphysema

Question 18

What is the pulmonary acinus?

Answer 18

Gas-exchanging unit of the lung and is defined as that portion of the lung distal to the terminal bronchiole which is composed of the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.

Question 19

Which part of the lungs is Centriacinar emphysema most common?

Answer 19

Upper part of the lungs

Question 20

Name some other types of emphysema.

Answer 20

Panacinar
Periacinar
Scar ‘irregular’

Question 21

Where is there tissue loss in periacinal emphysema?

Answer 21

Around the edges of the acinus

Question 22

What is a bulla?

Answer 22

Bulla is an emphysematous space greater than 1cm

Question 23

What happens if a bulla pops or leaks gas?

Answer 23

A pneumothorax may form as air leaks into the pleural space

Question 24

Which cells in the lungs can cause slight inflammation as they digest foreign substances?

Answer 24

Neutrophils and macrophages

Question 25

What do neutrophils and macrophages produce?

Answer 25

Elastase (protease)

Question 26

Why is it important that we don't have too much elastase in our lungs?

Answer 26

It digests the elastase framework of alveolar tissue

Question 27

What is the counteraction for elastase to maintain homeostasis?

Answer 27

Anti-elastase :)

Question 28

How effective are the repair mechanisms for the elastin synthesis in the lungs?

Answer 28

Very poor

Question 29

What is not present in those with alpha 1 antitrypsin deficiency?

Answer 29

Anti-elastase :(

Question 30

What does the lack of anti-elastase lead to?

Answer 30

Tissue destruction->emphysema

Question 31

What does smoking do to the production of elastase and antielastase?

Answer 31

Decreases ant elastase Increases activity of neutrophils and macrophages so there is more elastase produced

Question 32

Which part of the small airways may respond to drugs?

Answer 32

-smooth muscle tone -inflammation

Question 33

How does emphysema lead to obstructive airways?

Answer 33

Loss of alveolar attachments

Question 34

Name some factors which contribute to hypoxaemia.

Answer 34

Airway Obstruction Reduced Respiratory Drive Loss of Alveolar Surface Area Shunt - Only during severe acute infective exacerbation

Question 35

What happens to pulmonary arteriolar vasoconstriction when there is hypoxia?

Answer 35

All vessels constrict preventing blood from going to oxygen poor alveoli as gas exchange will not take place efficiently

Question 36

What is chronic cor pulmonary?

Answer 36

Hypertrophy of the Right Ventricle resulting from disease affecting the function and/or the structure of the lung.

Question 37

What is the main cause of death in patients with COPD?

Answer 37

Cor Pulmonale and right heart failure

Question 38

How does emphysema impacts blood vessels?

Answer 38

Reduces numbers of blood vessels.

Question 39

Explain Secondary polycythaemia

Answer 39

Bone marrow produces more red blood cells as not enough oxygen is carried around the body. However, this just increases viscosity of blood making it harder to be pumped.