Asthma Pathophysiology and Mechanisms

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Which of the following mechanisms contribute to airway narrowing in asthma?

Smooth muscle relaxation
Reduced mucous production
Mucosal swelling due to vascular leak (correct)
Decreased infiltration of bronchial walls by inflammatory cells

What changes are associated with long-term, poorly controlled asthma?

Decreased mucus gland size
Hypertrophy and hyperplasia of smooth muscle (correct)
Atrophy of smooth muscle
Thinning of the basement membrane

During an asthma, what causes ventilation-perfusion mismatch in the lungs?

Decreased residual volume
Increased ventilation of affected alveoli
Airway widening leading to increased airflow
Reduced ventilation of the affected alveoli (correct)

What blood gas analysis results would be expected in a patient experiencing a mild to moderate asthma attack?

Decreased pCO2 and decreased pO2 (A) Signup and view all the answers

Which of the following is a sign of life-threatening asthma?

Increased pCO2 (A) Signup and view all the answers

What role do eosinophils play in the airway inflammation associated with asthma?

Release of mediators that can be toxic to epithelial cells (D) Signup and view all the answers

A patient with asthma has an FEV1/FVC ratio of 65% on spirometry. After bronchodilator administration, the ratio increases to 75%. What does this indicate?

The patient has an obstructive pattern with reversibility. (B) Signup and view all the answers

How does hyperventilation affect blood gas levels in a patient with mild to moderate asthma?

It compensates for CO2 retention by decreasing pCO2. (C) Signup and view all the answers

Which of the following best describes the nature of airflow obstruction in asthma?

Widespread, but variable obstruction that is often reversible either spontaneously or with treatment. (B) Signup and view all the answers

In the pathophysiology of asthma, which type of T helper cells are primarily involved in driving the chronic inflammatory process?

Th2 cells (C) Signup and view all the answers

Exposure to an allergen results in a biphasic response. What is the primary mechanism behind the immediate response in an atopic asthmatic?

Interaction of the allergen and specific IgE antibodies, leading to mast cell degranulation. (C) Signup and view all the answers

What is the underlying hypersensitivity reaction responsible for the late phase response in sensitized asthmatics?

Type IV hypersensitivity (C) Signup and view all the answers

Which of the following is NOT typically considered a major precipitating factor for asthmatic attacks?

Ingestion of gluten-containing products. (D) Signup and view all the answers

The rise in asthma prevalence in developing countries that transition to developed countries can be attributed to what factor?

Increased exposure to airborne allergens and pollutants. (A) Signup and view all the answers

Which immunological process occurs when macrophages present antigens to T lymphocytes in asthma pathophysiology?

t ‘activates’ T cells, with TH2 cells being preferentially activated. (D) Signup and view all the answers

During the immediate response in asthma, what is the combined effect of histamine, tryptase, prostaglandin D2, and leukotrienes released from mast cells?

Bronchial smooth muscle contraction → bronchoconstriction. (D) Signup and view all the answers

Which of the following scenarios would most likely necessitate assisted ventilation in an asthma patient?

The patient presents with severe and extensive disease along with exhaustion. (B) Signup and view all the answers

A patient reports experiencing asthma symptoms primarily during the spring and when visiting friends with pets. Which triggers are most likely contributing to this patient's asthma?

Pollen and animal dander (B) Signup and view all the answers

Why might a doctor recommend allergy testing for a patient with asthma?

To identify specific allergens that trigger the patient’s asthma. (C) Signup and view all the answers

A patient with asthma has a persistent dry cough, especially at night, and experiences breathlessness during exercise. Auscultation reveals a polyphonic wheeze. Which additional finding would support this diagnosis?

Hyper-resonant percussion (B) Signup and view all the answers

A patient's spirometry results show a low FEV1/FVC ratio. After administering salbutamol, the FEV1 increases by 15%. What does this indicate?

The patient has a significant response to bronchodilator, suggesting reversible airway obstruction consistent with asthma. (C) Signup and view all the answers

Which of the following would be part of 'primary prevention' for asthma?

Reducing exposure to known allergens and triggers. (C) Signup and view all the answers

A patient with asthma is prescribed a bronchodilator. What is the primary purpose of this medication?

To dilate the airways and relieve symptoms of bronchoconstriction immediately. (D) Signup and view all the answers

Chest X-rays are typically performed in asthma patients for what reason?

To exclude other conditions such as foreign body inhalation or pneumothorax. (C) Signup and view all the answers

Asthma

Chronic inflammatory disorder with variable airflow obstruction and increased airway responsiveness.

Asthma Epidemiology

Asthma is becoming more prevalent, especially in developed countries and urbanized populations.

Asthma Risk Factors

Genetic predisposition, allergens (e.g., dust mites, pollens), pollution, and tobacco smoke.

Asthma Pathophysiology

Driven by Th2 cells activating inflammatory cells like mast cells and eosinophils, and IgE production by B cells.