Pathophysiology of bronchial asthma

Question 1

What is bronchial asthma

Answer 1

Chronic airway inflammation, associated with airway hyper responsiveness

Question 2

B. Asthma leads to…

Answer 2

bronchoconstriction (Reversible) and airflow limitation

Question 3

Clinical manifestation of bronchial asthma ?

Answer 3

Recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning.

Question 4

What is Airway hyper-reactivity

Answer 4

the tendency for airways to narrow excessively
in response to triggers that have little or no effect in normal individuals

Question 5

Types of asthma?

Answer 5

1. Atopic asthma
2. Non-atopic asthma

Question 6

Non-atopic asthma ..

Answer 6

• Drug-induced asthma
• Exercise-induced asthma
• Occupational asthma

Question 7

Causes of atopic asthma?

Answer 7

Causes: environmental allergens, such as dusts, pollens, cockroach or animal dander, and foods

Question 8

Causes of Non- atopic asthma?

Answer 8

✓ Respiratory viral infections,
✓ Air pollutants, e.g., tobacco smoke,
✓ Cold air, stress, exercise

Question 9

Mechanism of Non-atopic asthma ?

Answer 9

• Chronic airway inflammation and hyperreactivity
• Skin test - negative

Question 10

Drug-Induced Asthma

Answer 10

• Aspirin and non-steroidal anti-inflammatory drugs
• Beta-adrenoceptor antagonists (β-blockers)
• Oral contraceptive pill
• Cholinergic agents
• Prostaglandin F2α
• Betel nuts contain arecoline

Question 11

Cause of occupational asthma?

Answer 11

Causes: fumes (epoxy resins, plastics), organic and chemical dusts (wood, cotton, platinum), gases (toluene), or other chemicals (formaldehyde, penicillin products).

Question 12

Mechanism of occupational asthma ?

Answer 12

1) Type I hypersensitivity
2) Direct production of bronchoconstrictor substances
3) Hypersensitivity responses of unknown origin

Question 13

Mast cells release preformed mediators. Role preformed mediators?

Answer 13

1) Bronchospasm
2) Increased vascular permeability
3) Mucus production
4) Recruitment of leukocytes

Question 14

Leukotrienes C4, D4, and E4

Answer 14

1) Prolonged bronchoconstriction
2) Increased vascular permeability
3) Increased mucus secretion

Question 15

Acetylcholine

Answer 15

• Released from intrapulmonary parasympathetic nerves
• Bronchoconstriction by directly stimulating muscarinic receptors

Question 16

IL-5 are associated with

Answer 16

peripheral blood eosinophilia

Question 17

Galectin-10 (GAL10)

Answer 17

is released from eosinophils and forms
Charcot-Leyden crystals

Question 18

These crystals is a…

Answer 18

Strong inducers of inflammation and
mucus production

Question 19

Histamine cause?

Answer 19

bronchospasam

Question 20

Prostaglandin D2 cause?

Answer 20

bronchospasm and vasodilation

Question 21

Platelet activating factor cause?

Answer 21

Platelet aggregation and release serotonin

Question 22

Bronchial asthma phatogenesis?

Answer 22

1. Immune response
2. Genetic susceptibility
3. Environmental Factors

Question 23

Airborne pollutants can serve as

Answer 23

allergens to initiate the Th2 response

Question 24

Infections do not cause asthma by themselves but

Answer 24

may be important co-factors

Question 25

viral and bacterial infections are associated with

Answer 25

acute exacerbations of the disease

Question 26

Morphology of acute severe asthma (status asthmaticus)

Answer 26

Gross & Histology

Question 27

Gross of acute severe asthma

Answer 27

1. Overinflated lungs with small areas of atelectasis 2. Occlusion of bronchi and bronchioles by thick, tenacious mucus plugs, which often contain shed epithelium.

Question 28

Sputum or bronchoalveolar lavage contains ....

Answer 28

1) Curschmann spirals - mucus plugs from subepithelial mucous gland ducts or bronchioles 2) Charcot-Leyden crystals - eosinophil-derived protein galectin-10

Question 29

Histology of acute severe asthma

Answer 29

Numerous eosinophils

Question 30

Cause of Airway remodeling

Answer 30

Repeated bouts of allergen exposure

Question 31

Airway remodelling results in:

Answer 31

1) Bronchial smooth muscle hypertrophy and hyperplasia 2) Epithelial injury 3) Increased airway vascularity 4) Subepithelial mucous gland hypertrophy 5) Subepithelial fibrosis (deposition of type I and III collagens)

Question 32

Acute airflow obstruction is primarily due to

Answer 32

1. bronchocospasm 2. acute edema 3. mucus plug

Question 33

Chronic irreversible airway obstruction may be due

Answer 33

Airway remodeling

Question 34

What are the Clinical Features of acute asthmatic attack?

Answer 34

1. Lasts up to several hours 2. Recurrent episodes of wheezing, dyspnea, chest tightness, and cough 3. Precipitants: exercise (particularly in cold weather), airborne allergens or pollutants, and viral upper respiratory tract infections

Question 35

What are the Diagnosis of acute asthmatic attack?

Answer 35

* Difficulty with exhalation (prolonged expiration, wheeze) * An increase in airflow obstruction – spirometry, peak flow meter * Atopic asthma – eosinophilia, Curschmann spirals, and Charcot-Leyden crystals in the sputum, skin prick test

Question 36

Exacerbations of Asthma: Precipitant?

Answer 36

viral infections, moulds, pollens, and air pollutants

Question 37

Clinical feature of