Pulmonary Pathology Flashcards
What are the requirements for normal fetal lung development?
Space in the thoracic cavity + ability to inhale (chest wall must be able to move and there needs to be enough material (amniotic fluid) present to inhale)
Larger airways conduct air to what?
terminal acinar units for proper gas exchange
What is normal bronchial histology?
Ciliated respiratory epithelium, smooth muscle glands and submucosal glands, cartilage
What is the predominant histology in lung tissue?
alveolar/lung parenchyma
What are the cellular constituents of the alveolar sac and septum?
type I and I alveolar cells, RBCs, macrophages, fibroblasts, capillaries, endothelial cells and surfactant
What is normal alveolar structure?
Capillaries associated with endothelium, baememnt membrane with interstitium, alveolar pores of Kohn, alveolar epithelium
What is the function of the alveolar pores of Kohn?
Allow for maximal aeration but also bacteria, cells or fluid to travel between alveoli
What are the components of alveolar epithelium?
Type 1 pneumocytes which facilitate gas exchange; Type 2 pneumocytes which produce surfactant and replace type 1 pneumocytes
What is atelectasis?
An acquired incomplete expansion of lung parenchyma; three types: resorption (obstructive), compression, contraction
What is resorption (obstructive) atelectasis?
Airway obstruction with gradual resorption of air reduces lung expansion
What is compression atelectasis?
accumulated material in pleural cavity compresses the lung parenchyma
What is contraction atelectasis?
Fibrotic or other innate restrictive process in the pleura or peripheral lung restricts lung expansion
What is pulmonary edema?
Interstitial fluid (pink proteinaceous material) in the alveolar spaces
What are three causes of pulmonary edema?
hemodynamic pressure gradient, injury to alveolar wall, or unsure mechanisms including neurogenic (brain injury) and high altitude pulmonary edema (HAPE)
What are examples of hemodynamic forces pushing out fluid that can lead to pulmonary edema?
LHF, volume overload, pulmonary vein obstruction
What are examples of hemodynamic gradients causing leaking out of fluid that can result in pulmonary edema?
hypoalbuminemia, nephrotic syndrome, liver disease
What injuries to the alveolar wall can cause pulmonary edema?
Bacterial pneumonia, sepsis, smoke inhalation, aspiration
Increased hydrostatic pressure causes what?
forces fluid out
Decreased oncotic pressure results in what?
loses fluid through equilibrium across a semipermeable membrane
Describe the appearance of pulmonary congestion
Apparent with dilated capillaries full of blood; micro hemorrhage occurs in these congested into alveolar spaces; as a result scattered hemosiderin laden macrophages accumulate within alveoli known as HF cells because of their association with pulmonary congestion with CHF
What is acute lung injury?
A part of the ARDS spectrum; acute onset, hypoxemia, bilateral infiltrates, no evidence of cardiac failure; PaO2/FiO2 <300
What are the features of RLD?
volume restriction/reduction, FEV1/FVC normal, FVC reduced, decreased TLC, interstitial lung disease
What are the features of OLD?
Decreased flow, air trapping, low FEV1/FVC ratio, decreased FEV1, TLC increased
What are the mediators for bronchoconstriction seen in asthma?
Leukotrienes C4-D4-E4, histamine, prostaglandin D2, acetylcholine
What are the mediators for the mucus secretion seen in asthma?
leukotrienes C4-D4-E4
What are the mediators for the increased vascular permeability seen in asthma?
leukotrienes C4-D4-E4
What are the mediators for the recruitment of inflammatory cells seen in asthma?
Interleukins
What role does genetics play in atopic asthma?
Atopic asthma is associated with seasonal allergies and eczema; may be linked to various alleles controlling like IgE, cytokines (IL-4), adrenergic receptors, etc
What role does the environment play in atopic asthma?
Disease of industrialized societies (pollution, lack of allergen exposure at early age) + early infection
What is aspirin sensitive asthma?
Associated with nasal polyps and recurrent rhinitis (Samter’s triad); unique sensitivity to aspirin; cross reacts with other NSAIDs
What does lung transplant rejection show on biopsy?
Mononuclear infiltrates around vessels (acute rejection)
