Regarding non-atopic (intrinsic) asthma, which of the following statements is correct?
A Is mainly triggered by viral respiratory illnesses rather than bacterial
B Is associated with atopy
C Decreases vagal afferent responsiveness
D A positive family history is common
A Is mainly triggered by viral respiratory illnesses rather than bacterial
It is thought that the virus induced inflammation of the respiratory mucosa lowers the threshold of the subepithelial vagal receptors to irritants
Definition of asthma
Asthma is a chronic inflammatory disorder of the airways causing:
Reversible airflow obstruction
Airway hyperresponsiveness
Chronic airway inflammation
Pathophysiology of asthma
- Trigger exposure (allergens, infection, cold air, exercise, etc.)
- Th2 cell activation → cytokines:
IL-4: stimulates IgE production
IL-5: recruits eosinophils
IL-13: mucus production & IgE class switching - IgE binds mast cells → degranulation → histamine, leukotrienes, prostaglandins → bronchoconstriction, edema, mucus
Histopathology in Chronic Asthma
Goblet cell hyperplasia → ↑ mucus
Subepithelial fibrosis → thickened basement membrane
Smooth muscle hypertrophy
Eosinophilic infiltrate
Curschmann spirals: mucus plugs with shed epithelium
Charcot-Leyden crystals: eosinophil-derived crystals in sputum
What happens to most particles 1-5 micrometers in diameter after they are breathed in?
A Phagocytosed by pulmonary alveolar macrophages
B Deposited in nose
C Lodged in trachea and bronchi
D Exhaled away
A Phagocytosed by pulmonary alveolar macrophages
With regard to bronchial asthma, which of the following statements is correct?
A Sub-epitheleal vagal receptors in respiratory mucosa become desensitised to irritants
B IgG plays a role
C Bronchial wall smooth muscle is atrophic
D Primary mediators include eosinophilic and neutrophilic chemotactic factors
D Primary mediators include eosinophilic and neutrophilic chemotactic factors
Most asthma is associated with atopy, which represents an increased susceptibility to generate IgE in response to allergens.
The bronchial smooth muscle becomes hypertrophic.
Which of the following is a late change seen in an acute asthma attack?
A Mast cell degranulation
B Bronchoconstriction
C Vasodilation
D Epithelial cell damage
D Epithelial cell damage
The late inflammatory phase is characterized by persisting bronchospasm and edema, leukocyte infiltration, and eosinophil-mediated epithelial damage and loss.
