Summaries Chapter 13: The lung Flashcards
What does ARDS stand for?
Acute respiratory distress syndrome
What is ARDS?
ARDS is a clinical syndrome of progressive respiratory insufficiency caused by diffuse alveolar damage in the setting of sepsis, severe trauma, or diffuse pulmonary infection.
Which cells play an important role in the pathogenesis of ARDS and why?
Neutrophils and their products have a crucial role in the pathogenesis of ARDS by causing endothelial and epithelial injury
How can ARDS be characterized under an histologic picture?
Alveolar edema, epithelial necrosis, accumulation of neutrophils, and presence of hyaline membranes lining the alveolar wall and ducts.
What is emphysema?
Emphysema is a chronic obstructive airway disease characterized by enlargement of air spaces distal to terminal bronchioles.
What are subtypes of emphysema?
centriacinar (most common: smoking- related), panacinar (seen in α1-anti-trypsin deficiency), distal acinar, and irregular.
Fill in: Smoking and inhaled pollutants cause ongoing accumulation of inflammatory cells, which are the source of … such as elastases that irreversibly damage alveolar walls.
proteases
Patients with uncomplicated emphysema present with …. (symptoms)
increased chest volumes, dyspnea, and relatively normal blood oxygenation at rest (“pink puffers”)
What are the signs/symptoms of most patients with emphysema? (& Why)
concurrent chronic bronchitis, since cigarette smoking is a risk factor for both.
How is chronic bronchitis defined?
as persistent productive cough for at least 3 consecutive months in at least 2 consecutive years.
What is the most important risk factor for chronic bronchitis?
Smoking (but air pollutants may contribute)
Chronic airway obstruction largely results from big/small airway disease and coexistent …. (2 diseases)
small, chronic bronchiolitis and emphysema respectively
How does histologic examination of chronic bronchitis look like?
Histologic examination demonstrates enlargement of mucus-secreting glands, goblet cell metaplasia, and bronchiolar wall fibrosis.
How is asthma characterized?
by reversible bronchoconstriction caused by airway hyperresponsiveness to a variety of stimuli.
What is atopic asthma most often cause by? What are important mediators?
TH2 and IgE-mediated
immunologic reaction to environmental allergens. The TH2 cytokines IL-4, IL-5, and IL-13 are important mediators
What is atopic asthma characterized by?
early-phase (immediate) and late-phage reactions
What are triggers for nontoxic asthma?
Triggers for nonatopic asthma are less clear but include viral infections and inhaled air pollutants, which also can trigger atopic asthma.
What are key inflammatory cells that are found in all subtypes of asthma, and how?
Eosinophils, the products of oesinophil (such as major basic protein) are responsible for airway damage
What adds an irreversible component to asthma?
Airway remodeling (sub-basement membrane thickening and hypertrophy of bronchial glands and smooth muscle)
Is asthma restrictive or obstructive?
Obstructive
Diffuse interstitial fibrosis of the lung gives rise to restrictive lung diseases characterized by increased/reduced lung compliance and increased/reduced forced vital capacity
Reduced and reduced
Is the FEV to FVC ration normal in chronic interstitial lung diseases?
Yes
Diseases that cause diffuse interstitial fibrosis are heterogeneous/homogeneous
heterogeneous
What is the unifying pathogenic factor of chronic interstitial lung diseases?
Injury to the alveoli, leading to activation of macrophages and release of fibrogenic cytokines such as TGF-β