Pathophysiology of ARDS and Asthma

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What is the primary underlying cause of Acute Respiratory Distress Syndrome (ARDS)?

Inadequate expansion of air spaces leading to atelectasis.

Injury to the epithelial and endothelial linings of the alveolar-capillary membrane. (correct)

Release of pro-inflammatory mediators such as IL-1 and TNF.

Activation and sequestration of neutrophils in pulmonary capillaries.

What is the primary mechanism by which atelectasis contributes to hypoxemia?

Release of pro-inflammatory mediators, causing endothelial dysfunction and reduced gas exchange.

Activation of neutrophils leading to inflammation and fluid buildup in the lungs.

Obstruction of airways, preventing air from reaching the lungs.

Increased ventilation-perfusion imbalance due to perfusion of atelectatic lung. (correct)

What is the role of neutrophils in the pathogenesis of ARDS?

Neutrophils release pro-inflammatory mediators that contribute to the inflammatory cascade.

Neutrophils cause obstruction of airways by forming clumps in the air sacs.

Neutrophils directly damage the epithelial and endothelial linings of the alveolar-capillary membrane.

Neutrophils contribute to the inflammatory response and are implicated in the damage observed in ARDS. (correct)

What type of atelectasis occurs when an obstruction prevents air from reaching distal airways?

Obstruction atelectasis (A) Signup and view all the answers

What is the direct effect of pro-inflammatory mediators like IL-1 and TNF on the pathogenesis of ARDS?

They activate neutrophils, leading to a cascade of inflammatory events. (D) Signup and view all the answers

What is the primary function of the goblet cells in a healthy airway?

Produce mucus to trap foreign particles (A) Signup and view all the answers

Which of the following is NOT a characteristic of the late phase of asthma?

Release of histamine from mast cells (A) Signup and view all the answers

In an airway affected by asthma, the subepithelial basement membrane becomes thickened. What is the primary contributor to this thickening??

Inflammation and deposition of collagen (B) Signup and view all the answers

Which cell type is NOT directly involved in triggering the immediate phase of an asthma response?

Neutrophils (A) Signup and view all the answers

What is the role of IgE in asthma?

Binds to allergens and triggers mast cell degranulation (A) Signup and view all the answers

Which of the following is NOT a characteristic feature of asthma?

Reduced airway inflammation (A) Signup and view all the answers

What is the role of dendritic cells in triggering asthma?

Present allergens to T cells (D) Signup and view all the answers

Which of the following is a key mediator released by mast cells in the immediate phase of asthma?

Histamine (C) Signup and view all the answers

Which of the following is the primary driving force for bronchoconstriction in asthma?

Contraction of smooth muscle cells in airway walls (D) Signup and view all the answers

What is a characteristic histological finding in the early stages of IPF?

Exuberant fibroblastic proliferation forming fibroblastic foci (B) Signup and view all the answers

Which of the following clinical presentations is highly suggestive of IPF?

Gradual onset of non-productive cough and progressive dyspnea (D) Signup and view all the answers

What is the underlying mechanism responsible for the reduction in lung compliance in patients with IPF?

Thickening of the alveolar walls due to fibrosis (A) Signup and view all the answers

In the advanced stages of IPF, what characteristic radiographic finding may be observed?

Honeycomb fibrosis with cystic spaces (C) Signup and view all the answers

Which of the following cells is typically involved in the interstitial inflammation associated with IPF?

Lymphocytes (A) Signup and view all the answers

What is the underlying cause of hypoxia in patients with IPF?

Decreased diffusion capacity of the alveoli due to thickened alveolar walls (C) Signup and view all the answers

Which of the following pathological changes is a common consequence of pulmonary hypertension in IPF?

Thickening of the pulmonary artery walls (B) Signup and view all the answers

What is the most characteristic physical examination finding associated with IPF?

Dry, velcro-like crackles during inspiration (C) Signup and view all the answers

What percentage of heavy smokers develop COPD?

35-50% (A) Signup and view all the answers

Which of the following is NOT a risk factor for developing COPD?

Regular exercise (C) Signup and view all the answers

What is the primary cause of COPD in approximately 80% of cases?

Smoking (A) Signup and view all the answers

Which of the following best describes the defining characteristic of emphysema?

Permanent enlargement of air spaces distal to the terminal bronchioles (C) Signup and view all the answers

What is the main distinction between emphysema and chronic bronchitis, as outlined in the text?

Emphysema involves permanent enlargement of air spaces, while chronic bronchitis is characterized by inflammation and mucus production. (C) Signup and view all the answers

What is the significance of understanding the anatomical distribution of emphysema?

It allows for more accurate diagnosis and prognosis. (D) Signup and view all the answers

Why does the text emphasize that emphysema is characterized by destruction of the walls of air spaces "without significant fibrosis"?

Fibrosis indicates a different disease process than emphysema. (A) Signup and view all the answers

Which of the following scenarios is most likely to result in a significant exacerbation of emphysema?

An individual with a history of cigarette smoking develops a severe respiratory infection. (A) Signup and view all the answers

Which of the following statements accurately describes the role of a1-antitrypsin in the pathogenesis of emphysema?

It inhibits the activity of proteases, primarily elastase, which are involved in the breakdown of lung tissue. (D) Signup and view all the answers

Which of the following genetic factors significantly increases the risk of developing emphysema?

Homozygosity for the Z allele of the proteinase inhibitor (Pi) locus, leading to reduced a1-antitrypsin levels. (C) Signup and view all the answers

How does environmental irritant exposure contribute to the development of chronic obstructive pulmonary disease (COPD)?

It triggers a cascade of inflammatory events, including the release of proteases, contributing to lung tissue destruction. (A) Signup and view all the answers

Based on the information provided, which of the following is NOT a major contributing factor to the development of emphysema?

The overproduction of surfactant. (B) Signup and view all the answers

What is the primary mechanism by which the loss of elastic tissue in the alveoli contributes to airway obstruction in emphysema?

It reduces the recoil of the lung parenchyma, leading to decreased radial traction on the small airways. (A) Signup and view all the answers

The statement "About 1% of patients with emphysema have this defect" refers to which defect?

An inherited deficiency of the antiprotease a1-antitrypsin. (B) Signup and view all the answers

Which of the following is NOT a direct consequence of environmental irritant exposure on the airways, according to the provided information?

Destruction of alveolar septa. (D) Signup and view all the answers

Which of the following is NOT a characteristic feature that distinguishes CWP from silica and asbestos exposures?

Presence of coal macules and nodules (D) Signup and view all the answers

Which of the following is the most common crystalline form of silica implicated in silicosis?

Quartz (C) Signup and view all the answers

What is the primary effect of silica particles on alveolar macrophages, leading to the development of silicosis?

Cause lysosomal damage, leading to activation of the inflammasome (B) Signup and view all the answers

Which of the following is NOT a reason why workers involved in sandblasting and hard-rock mining are at a particularly high risk for silicosis?

These occupations involve high-intensity physical exertion, increasing the risk of silica inhalation (A) Signup and view all the answers

Which of the following statements is accurate regarding the difference between Simple CWP and Complicated CWP?

Simple CWP is characterized by coal macules and nodules, while Complicated CWP is characterized by large, dense scars (D) Signup and view all the answers

What is the significance of pulmonary anthracosis being commonly seen in individuals who smoke tobacco?

It highlights the difficulty in distinguishing between CWP and the effects of tobacco smoke (B) Signup and view all the answers

Which of the following is NOT a characteristic of Complicated CWP (PMF)?

Can be caused by prolonged exposure to asbestos fibers (D) Signup and view all the answers

What is the main difference between the pathogenesis of silicosis and CWP?

Silicosis is caused by the inhalation of crystalline silica, while CWP is caused by the inhalation of carbon pigment (D) Signup and view all the answers