pathology of lung disease

Question 0

which cells in the lungs make mucus

Answer 0

goblet cells

Question 1

what epithelium is found in the lungs

Answer 1

pseudostratified ciliated columnar epithelium

Question 2

whats the difference between type 1 and 2 pneumocytes

Answer 2

type 1 are flattened and make up 95% of the alveolar surface. type 2 are rounded and make surfactant.

Question 3

define FEV1

Answer 3

• Forced expiratory volume in 1 sec. the volume that can be forcibly exhaled in the first second of forced expiration.

Question 4

define FVC

Answer 4

forced vital capacity. the maximum volume of air that can be forcibly exhaled out of the lung until no more can be expired.

Question 5

whats the lung TLC

Answer 5

total lung capacity.

Question 6

whats the lung PEFR

Answer 6

peak expiratory flow rate. max flow achieved during forced expiration.

Question 7

6 causes of obstructive lung disease

Answer 7

acute - foreign bodies, bronchiolitis

recurrent acute - asthma

chronic - chronic brochitis, emphysema, bronchiectasis.

Question 8

define chronic bronchitis

Answer 8

chronic sputum production usually accompanied by chronic cough, occuring on most days for three months of the year, for 2 or more consecutive years.

Question 9

pathogenesis of chronic bronchitis

Answer 9

1 - chronic irritation eg cigarrette smoke or air pollution
2 - mucus hypersecretion to protect, submucosal gland hypertrophy and hyperplasia in the larger airways, increased numbers of goblet cells in small airways.
3 -damage and death of ciliated cells (reduced mucociliary action), secondary infection, inflammation and fibrosis.

• partially reversible on stopping smoking.

Question 11

what is cor pulmonale

Answer 11

Pulmonary heart disease (New Latin pulmōnāle, of the lungs), also known as Cor pulmonale (Latin cor, heart + of the lungs) is the enlargement and failure of the right ventricle of the heart as a response to increased vascular resistance or high blood pressure in the lungs (pulmonary hypertension).

Question 12

what is emphysema

Answer 12

Definition is Pathological:

An abnormal permanent increase in the size of air spaces beyond the terminal bronchioles with destruction of their walls but without fibrosis

In a highly compliant lung, as in emphysema, the elastic tissue is damaged by enzymes. These enzymes are secreted by leukocytes (white blood cells) in response to a variety of inhaled irritants, such as cigarette smoke. Patients with emphysema have a very high lung compliance due to the poor elastic recoil, they have no problem inflating the lungs but have extreme difficulty exhaling air. In this condition extra work is required to get air out of the lungs. Compliance also increases with increasing age.

Question 13

what are the subclassificatiojns of emphysema

Answer 13

---Centriacinar (centrilobular) 
> common
-cigarette smoking
-chronic bronchitis
-upper zones of lung
-secondary to airway inflammation (increased protease activity)

—-Panacinar (panlobular)
-α1 – antitrypsin deficiency
(decreased anti-protease activity)
-lower zones of lung
-Homozygotes (PiZZ) onset <40 yrs
-Heterozygotes must smoke

Question 14

histopath appearance of end stage empysema

Answer 14

End-stage
emphysema has
cystic alveolar spaces
visible macroscopically

• alevoli are dilated and their boundaries broken.

Question 15

Lung Function Tests n empysema

Answer 15

Reduced FEV1 to <0.7)

Reduced PEF

Increased TLC

Also reduced diffusion capacity

loss of the elastic recoil causes premature closure of the small airways (decreased radial traction causes collapse).

Question 16

what is COPD

Answer 16

Chronic obstructive pulmonary disease

Defined by lung function tests

Combination of bronchitis & emphysema

Secondary to smoking

Most have mixture of symptoms

‘Pure’ disease at each end of spectrum

Question 17

COPD Treatment and Prognosis

Answer 17

Prevention & supportive therapy
Stop smoking

Oxygen therapy if hypoxic
Pulmonary rehabilitation (exercise & education programme for patients to increase mobility, understand their disease, cope with their breathlessness by pacing their activities, improve anxiety and depression)

5-10% of all deaths in UK

Question 18

COPD complications

Answer 18

Pneumonia

Respiratory failure

Pulmonary hypertension

Cor pulmonale

Polycythaemia

Pneumothorax

Question 19

asthma definition, hallmarks and incidence.

Answer 19

Definition is largely clinical:

Paroxysmal wheezing and shortness of breath caused by acute, reversible narrowing of airways

Hallmarks:
hyper-reactive airways
inflammation (bronchial walls)
increased mucus secretion

Affects 8% of the population and incidence increasing

Question 20

subclassification of asthma

Answer 20

Extrinsic (Immune)
Atopic (allergic) asthma
Occupational asthma
Drug-induced asthma
Allergic bronchopulmonary aspergillosis
Non-atopic asthma 

Intrinsic (Non-immune)

Question 21

what is atopic asthma

Answer 21

Most common type of asthma
Type I hypersensitivity reaction
Environmental antigens
Dust, Pollen, Animal dander, Food
M >F, childhood onset
Family history of atopy
Gene as yet unknown 
Skin test positive - ‘Wheal & flare’

Question 22

what is intrinsic asthma

Answer 22

2nd most common type of asthma
Hyper-irritability of airways
Triggered by diverse, non-immune mechanisms 
pollution, viral infection etc
 F>M, adult-onset
No family history or other atopy
IgE levels normal
Skin test negative

Question 23

WHAT IS Occupational asthma

Answer 23

Type I & III hypersensitivity
Various inhaled agents:
Formalin, Plastics, Wood, Platinum

Question 24

what is Drug-induced asthma

Answer 24

Aspirin

Also have nasal polyps & skin urticaria

Question 25

what is Allergic bronchopulmonary aspergillosis

Answer 25

Type I & III hypersensitivity | Inhalation of aspergillus spores

Question 26

3 stages of asthma

Answer 26

``` Priming or Sensitization (1st exposure) Th2 response IgE production Eosinophil recruitment ``` Re-exposure ``` Immediate Mast cell degranulation Bronchospasm vascular permeability Oedema ``` Late Eosinophils & Inflammation Epithelial damage Airway constriction

Question 27

how is the airway obstructed in asthma

Answer 27

Acute response - immediate Smooth muscle spasm Mucosal oedema Late phase reaction – 12-24 hours Epithelial damage and inflammation Mucous exudation Chronic Phase – with repetition Mucous gland hyperplasia Smooth muscle hypertrophy Bronchial BM thickening

Question 28

generic treatment of asthma

Answer 28

Inhaled steroids (mainstay of treatment) Bronchodilators (symptom relief) Avoidance of allergen + systemic steroids for acute exacerbations

Question 29

complications of asthma

Answer 29

Status asthmaticus Pneumonia Bronchiectasis Cor pulmonale

Question 30

define bronchiectasis

Answer 30

Permanent dilation of bronchi and bronchioles caused by destruction of the muscle and elastic tissue, resulting from or associated with chronic necrotizing infections.

Question 31

3 causes of bronchiectasis

Answer 31

Congenital or hereditary conditions Postinfection Bronchial obstruction

Question 32

morphology of the lungs with bronchiectasis

Answer 32

Usually affects the lower lobes bilaterally Bronchial dilatation Most severe in distal bronchi and bronchioles ``` Spectrum of histological changes varies with the activity and chronicity of the disease Inflammation Ulceration Necrosis Fibrosis (bronchiolitis obliterans) ``` Superimposed infection

Question 33

complications of bronchiectasis

Answer 33

Respiratory insufficiency Cor pulmonale Brain abscess Amyloidosis

Question 34

what are interstitial lung diseases?

Answer 34

A heterogenous group of diseases Mostly immune mediated Share interstitial inflammation & fibrosis CXR shows an bilateral infiltrative pattern small nodules, irregular lines or ground-glass shadows Restrictive pattern on lung function tests reduced lung compliancy and gas exchange

Question 35

8 causes/associations of interstitial lung diseases

Answer 35

``` Pneumoconioses Systemic CT (auto-immune) diseases Sarcoidosis Post radiation or chemotherapy Post ARDS Idiopathic pulmonary fibrosis Wegener’s granulomatosus Goodpasture’s Syndrome ```

Question 36

what is pneumoconosis

Answer 36

Term originally for inorganic particles only Now also includes organic particles & chemical fumes Inorganic particles cause direct interstitial fibrosis Organic particles cause inflammation then fibrosis Fumes cause ARDS then fibrosis Organic particles & fumes can also cause asthma

Question 37

what is inorganic pneumoconiosis

Answer 37

Coal dust: Anthracosis Silica: Silicosis Asbestos: Asbestosis Often clinically insignificant Progressive massive fibrosis when significant respiratory compromise Most common with coal & silica Caplan’s syndrome if associated RA Nodules of fibrosis and chronic inflammation in interstitium

Question 38

what is organic pneumoconiosis

Answer 38

Farmer’s lung: Actinomycetes in mouldy hay Bird fancier’s lung: Animal proteins from faeces ``` aka extrinsic allergic alveolitis aka hypersensitivity pneumonitis Sensitisation to organic inhaled antigen Initial type III hypersensitivity reaction Later type IV hypersensitivity reaction ``` Interstitial inflammation by lymphocytes & often also granulomas, then later fibrosis

Question 39

what is sarcoidosis

Answer 39

``` Systemic disease of unknown aetiology F>M, Black>>White>>Asian Probable response to antigen Activated T-cells & macrophages Hilar LN or lung involvement in 90% Skin, LN & kidney involvement common Raised serum ACE & often high calcium ``` Non-necrotising granulomatous inflammation

Question 40

what is idiopathic pulmonary fibrosis

Answer 40

``` aka cryptogenic fibrosing alveolitis aka usual interstitial pneumonitis aka Hamman-Rich syndrome when rapidly progressive M>F, 60+ years Interstitial pneumonitis & fibrosis Cause unknown ``` Extensive interstitial fibrosis with alveolar distortion and interstitial expansion

Question 41

what happens in the end stage of interstitial fibrosis?

Answer 41

End stage ‘honeycomb’ lung: Interstitial fibrosis leading to cystic air-spaces cystic air spaces are smaller than those seen in bronchiectasis but far far more frequent. literally like a honeycomb.

Question 42

complications of pulmonary fibrosis

Answer 42

Respiratory failure Pulmonary hypertension Cor pulmonale

Question 43

treatment of interstitial lung diseases

Answer 43

Pneumoconiosis: Stop exposure to stop progression Any damage irreversible Other interstitial lung diseases: Steroid or further immunosuppression Response variable Often progress to significant fibrosis