Asthma Pathophysiology and Triggers

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

Localized obstruction primarily affecting the upper respiratory tract
Widespread but variable obstruction that is often reversible spontaneously or with treatment (correct)
Fixed and irreversible narrowing of the airways due to structural damage
Consistent and predictable reduction in airflow based on exposure to specific allergens

What is the primary immunological mechanism driving the chronic inflammatory process in asthma?

Predominant activation of cytotoxic T cells (CD8+)
Suppression of the adaptive immune response
Overproduction of IgA antibodies
Chronic inflammatory process driven by Th2 cells (correct)

In the context of asthma pathophysiology, what role do macrophages play?

Directly causing bronchoconstriction through smooth muscle contraction
Producing and releasing histamine
Processing and presenting antigens to T lymphocytes (correct)
Neutralizing IgE antibodies

Which type of hypersensitivity reaction is primarily associated with the immediate response in sensitized atopic asthmatics upon exposure to an allergen?

Type I hypersensitivity (A) Signup and view all the answers

What is the main mechanism by which the 'late phase response' contributes to the pathology of asthma?

Inflammation and infiltration of eosinophils contributing to airway hyperreactivity (A) Signup and view all the answers

Which of the following is an accurate observation regarding the epidemiology of asthma?

Asthma prevalence tends to increase in populations migrating from developing to developed countries. (C) Signup and view all the answers

What is the role of IgE antibodies in the pathophysiology of asthma?

Interacting with allergens to trigger mast cell degranulation and release of inflammatory mediators (C) Signup and view all the answers

Exposure to which of the following is most likely to trigger an asthmatic response, particularly in sensitized individuals?

House dust mite allergens (C) Signup and view all the answers

Which of the following cellular changes contributes to airway narrowing in asthma?

Hyperplasia of goblet cells (B) Signup and view all the answers

In long-term, poorly controlled asthma, airway remodeling can occur. Which of these is a feature of this remodeling?

Hypertrophy of smooth muscle (D) Signup and view all the answers

What is the effect of reduced ventilation of alveoli on gas exchange?

Ventilation/perfusion mismatch (C) Signup and view all the answers

What is the result on spirometry of the effect of airway narrowing?

Obstructive pattern (D) Signup and view all the answers

In mild to moderate asthma, what blood gas findings are typically observed?

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

Why might pCO2 levels increase to dangerous levels during a severe asthmatic attack?

Limited respiratory effort due to exhaustion prevents sufficient $CO_2$ expulsion (C) Signup and view all the answers

Which of the following best describes the role of leukotrienes in asthma?

Causing epithelial cell damage (C) Signup and view all the answers

A patient with asthma has a blood gas analysis showing increased pCO2 and decreased pO2. What does this indicate?

Type 2 respiratory failure (D) Signup and view all the answers

A patient with severe and extensive asthma is likely to require what type of intervention due to their condition?

Assisted ventilation. (C) Signup and view all the answers

Which of the following workplace scenarios is most likely to trigger an asthma attack in a susceptible individual?

Working in a factory using isocyanates and acid anhydrides. (D) Signup and view all the answers

Why is it important to understand that wheezing in asthma is described as 'polyphonic'?

It suggests multiple airways are affected, producing varying intensity and tone. (B) Signup and view all the answers

How does the typical presentation of an asthma-related cough differ from a cough caused by a respiratory infection?

Asthma-related cough is often worse at night and is typically dry. (D) Signup and view all the answers

During a physical examination of a patient with suspected asthma, which finding is LEAST likely to be observed?

Excessive energy and alertness. (B) Signup and view all the answers

Following a spirometry test and administration of salbutamol, what percentage increase in FEV1 would strongly suggest a diagnosis of asthma?

An increase of more than 12%. (A) Signup and view all the answers

What is the primary goal of educating asthma patients about their condition and treatment?

To empower patients to recognize symptoms, use medication correctly, and develop a personal asthma action plan. (D) Signup and view all the answers

According to the British Thoracic Society (BTS) stepwise approach, what is the main purpose of bronchodilators in asthma treatment?

To dilate the airways and provide symptomatic relief during an asthma attack. (C) Signup and view all the answers

Asthma Definition

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

Asthma Prevalence

Increasing globally, especially in developed countries and populations moving to them.

Asthma Risk Factors

Genetic predisposition, airborne allergens, air pollution, tobacco smoke, and hygiene hypothesis.

Asthma Pathophysiology

Driven by Th2 cells, leading to inflammation, mast cell and eosinophil activation, and IgE production.