Respiratory: Pathology - Pathology of obstructive airways disease

Question 1

What are the two types of distinctive lung diseases?

Answer 1

 Obstructive lung disease

 Restrictive lung disease

Question 2

How can the airways be narrowed/obstructed?

Answer 2

• Muscle spasm
• Mucosal Oedema
• Airway collapse
• Localised obstruction due to tumour/foreign body

Question 3

What are the two main respiratory obstructive diseases?

Answer 3

• Asthma

- COPD

Question 4

What is chronic bronchitis?

Answer 4

A cough productive of sputum on most days for 3 months of at least 2 successive years

Question 5

What does chronic irritation of the airways leads to?

Answer 5

leads to a defensive increase in mucous production with an increase in the numbers of epithelial cells; in particular, goblet cells

Question 6

What are the symptoms of chronic obstructive disease?

Answer 6

• Chronic Irritation
• Non-reversible obstruction
• May be a reversible asthmatic component
• Small airways
• Goblet cell metaplasia
• Macrophage accumulation
• Fibrosis around bronchioles

Question 7

What is emphysema?

Answer 7

 Increase beyond the normal size of the airspaces distal to the terminal bronchiole (the gas-exchanging compartment of the lung)

Question 8

What are the pattern types of emphysema?

Answer 8

o	Centriacinar (centrilobular) – around bronchioles
o	Panacinar – around lobes, lung appears generally ‘ragged’
o	Others (e.g. localised around scars in the lung)

Question 9

How can emphysema be diagnosed?

Answer 9

• reduced breath sounds

- Radiology CT

Question 10

What is the dilation in emphysema related too?

Answer 10

o Loss of alveolar walls - tissue destruction.
o Holes appear in lung tissue
o Loss of elastic recoil and support of small airways leading to tendency to collapse with obstruction
o Loss of support on bronchiolar walls

Question 11

What are the chronic effects of COPD?

Answer 11

• PaO2 decrease leads to
   Dyspnoea (shortness of breath) and increased respiratory rate
   Pulmonary vasoconstriction (and pulmonary hypertension

Question 12

What is the epidemiology of COPD?

Answer 12

• Smoking
• Atmospheric pollution
• Genetic factor

Question 13

What does a high rate of emphysema suggest?

Answer 13

Alpha-1-antitrypsin deficiency

Question 14

What is the pathology of emphsema?

Answer 14

• Proteases breaks down the protein walls
• Elastases
• Alpha-1-antitrypsin acts as an anti-elastase

Question 15

What does Alpha-1-antitrypsin act as?

Answer 15

An anti-elastase

Question 16

What actions does Tobacco smoke on the body?

Answer 16

• Increases number of neutrophils and macrophages in lung
• Slows transit of these cells
• Promotes neutrophil degranulation
• Inhibits alpha-1 antitrypsin

Question 17

What is Bronchial asthma?

Answer 17

A chronic inflammatory disorder characterised by hyperreactive airways leading to episodic reversible bronchoconstriction

Question 18

What is the pathology of bronchial asthma?

Answer 18

 Narrowed oedematous airways
 Mucus plugs
 Inflammatory cells (lymphocytes, plasma cells, eosinophils)
 Epithelial cell damage

Question 19

What is asthma?

Answer 19

 Type 1 hypersensitivity - allergen binds to IgE on surface of mast cells
 Degranulation (histamine)
o muscle spasm
o inflammatory cell influx (eosinophils)
o inflammation/oedema
 Inflammatory infiltrate tends to chronicity