Respiratory

Question 1

3 basic types of atelectasis

Answer 1

1. Resoprtion - after complete obstruction eg excessive bronchial secretions
2. Compressive - pleural space expanded by fluid eg effusion
3. Patchy - loss of surfactant eg IRDS

Question 2

Histology of pulmonary oedema

Answer 2

Engorged capillaries
Filling of airspace’s with granular pink pink precipitate

Question 3

3 classifications of pulmonary oedema

Answer 3

Harmodynamic oedema
Oedema due to microvascular injury
Oedema of undetermined origin

Question 4

Causes of increased hydrostatic pressure causing haemodynamic oedema

Answer 4

Left sided heart failure
Mitral stenosis
Volume overload
Pulmonary vein is obstruction
(Increase pulmonary venous pressure)

Question 5

Causes of decreased oncotic pressure causing haemodynamic oedema in the lungs

Answer 5

Hypoalbunaemia
Nephrotic syndrome
Liver disease
Protein losing enteropathies

Question 6

3 causes of haemodynamic oedema causing pulmonary oedema

Answer 6

Increased hydrostatic pressure
Decreased oncotic pressure
Lymphatic obstruction

Question 7

Causes of pulmonary oedema due to microcsacular injury

Answer 7

Infections
Inhaled gas
Liquid aspiration
Drugs and chemicals eg chemo
Shock/trauma
Radiation
DIC
Transfusion related

Question 8

2 causes of pulmonary oedema of undetermined origin

Answer 8

High altitude
Neurogenic

Question 9

Define acute respiratory distress syndrome

Answer 9

Diffuse alveolar capillary damage that leads to severe pulmonary oedema, respiratory failure and arterial hypoxia

Question 10

Top 4 conditions associated with ARDS

Answer 10

Sepsis
Diffuse pulmonary infections
Gastric aspiration
Mechanical trauma

Question 11

Mechanism of injury in Acute Respiratory Distress

Answer 11

Activation of lung macrophages which release oxidants, proteases, pro inflammatory cytokines
Causes aggregation of activated neutrophils secreted onjurious factors
Damage to endothelium and epithelium
Loss of surfactant = atelectasis
Increased alveolar permeability = pulmonary oedema

Question 12

Morphology of acute respiratory distress syndrome

Answer 12

Diffuse alveolar damage - oedema, hyaline membranes, acute inflammation
Patchy interstitial fibrosis and type II epithelial proliferation

Question 13

In ARDS what forms hyaline membranes

Answer 13

Composed of necrotic epithelial cell debris and exuded protein

Question 14

Definition and example of obstructive pulmonary disease

Answer 14

Increased resistance to air flow
Emphysema
Chronic bronchitis
Bronchiectasis
Asthma

Question 15

Definition and example of restrictive disease

Answer 15

Decreased expansion of lung parenchyma
Chest wall disorders
Acute or chronic interstitial or infiltration diseases

Question 16

Define emphysema

Answer 16

Abnormal enlargement of airspace’s distal to the terminal bronchioles, with destruction of their walls

Question 17

4 classifications and causes of emphysema according to anatomical distribution

Answer 17

1. Centriacinar emphysema - seen on tobacco smoking
2. Panacinar - uniform distraction and enlargement, predominance in the lower zones, associated with alpha 1 antitrypsin deficiency
3. Paraseptal - involves distal acinus, often underlying lesion of spontaneous pneumothorax
4. Irregular - bullous emphysema

Question 18

Explain the protease-antiprotrease hypothesis causing emphysema

Answer 18

Imbalance between proteases and their inhibitors in the lung
Emphysema invariably results in hereditary deficiency of the major protease inhibitor alpha 1 antitrypsin

Question 19

How does smoking contribute to emphysema

Answer 19

Activating alveolar macrophages
Secrete chemotactic factors
Recruit neutrophils
Stimulate release of elastase from neutrophils
Enhance macrophage elastase activity
Inactivating alpha 1 antitrypsin by oxidants in tobacco smoke and free radicals in neutrophils

Question 20

Define chronic bronchitis

Answer 20

Persistent cough with sputum production for at least 3 months in at least 2 consecutive years

Question 21

Morphology of chronic bronchitis

Answer 21

Hyperaemia and oedema of mucus membranes of the lung
Mucinous secretions
Increased size in mucus glands
Mucus plugging inflammation fibrosis
Squamous metaplasia/dysplasia of bronchial epithelium

Question 22

Pathogenisis of chronic bronchitis

Answer 22

Chronic irritation of the airways
Hyper secretion of mucus
Hypertophy of mucus glands
Goblet cell metaplasia bronchiolitis

Question 23

What are the 2 major types of asthma

Answer 23

Extrinsic atopic allergin mediated
Intrinsic nonreaginic (idiopathic)

Question 24

What type of hypersensitivity is asthma

Answer 24

Type 1 IgE mediated

Question 25

What happens in the acute phase in asthma

Answer 25

Binding of antigen IgE coated mast cells Release primary mediators (leukotrienes) Then release secondary mediators (cytokines) Cause bronchospasm, oedema, mucus secretion, recruitment of leukocytes

Question 26

What happens in the late phase reaction of asthma

Answer 26

Mediated by recruited leukocytes Persistent bronchospasm and oedema Leokocytic infiltration Loss of damaged epithelial cells

Question 27

What is the morphology in asthma

Answer 27

Lungs are overinflated, show patchy atelectasis with occlusion of airways by mucus plugs

Question 28

In asthma what are curschmann spirals

Answer 28

Whorled mucus plugs

Question 29

In asthma what are Charcot Leyden crystals

Answer 29

Crystalloid debris of eosinophil membranes within airways

Question 30

What is seen microscopically in asthma

Answer 30

Oedema Inflammatory infiltrate with numerous eosinophils Hypertrophy of bronchial wall musculature and mucous glands Whorled mucous plugs Crystalloid debris of eosinophil membranes within airways