Which hormone is the only one in the body that lowers blood glucose levels, and where is it produced?
Insulin, produced by the beta cells of the pancreas.
Name at least three major risk factors for development of COPD.
Major risk factors for COPD include smoking, alpha‑1 antitrypsin deficiency, asthma or airway hyperresponsiveness, and exposure to indoor or outdoor pollutants.
List four common clinical manifestations of an acute asthma exacerbation.
Common manifestations include wheezing, dyspnea, chest tightness, prolonged expiration, tachypnea, accessory muscle use, anxiety, and coughing.
Describe the key clinical features and primary treatment goals of acute respiratory distress syndrome (ARDS).
ARDS presents with rapid onset of severe hypoxemia, tachypnea, and respiratory distress that is refractory to oxygen therapy. Treatment goals include maintaining adequate oxygenation, treating the underlying cause, preventing further lung injury, and reducing mortality.
What are the classic “three P’s” of diabetes mellitus, and what causes polyuria in hyperglycemia?
Explain how obstructive airway diseases affect expiratory airflow and why expiration is more impaired than inspiration.
Obstructive airway diseases limit airflow primarily during expiration due to airway narrowing, inflammation, excess mucus, and loss of elastic recoil.
Identify common clinical manifestations of pulmonary embolism and explain why hypoxemia occurs.
Common manifestations include dyspnea, tachypnea, chest pain, tachycardia, fatigue, and hypoxemia. Hypoxemia occurs due to impaired gas exchange caused by obstruction of pulmonary blood flow and ventilation–perfusion mismatch.
Explain why expiration is prolonged during an asthma attack.
Expiration becomes prolonged due to airway narrowing from bronchospasm, mucosal edema, and mucus plugging, which increases resistance to airflow during exhalation.
Which type of diabetes is most at risk for developing diabetic ketoacidosis (DKA), and why?
Type 1 diabetes, due to an absolute lack of insulin.
Compare the pathophysiology of emphysema and chronic bronchitis, focusing on how each condition contributes to airflow obstruction.
Emphysema causes airflow obstruction through destruction of alveolar walls and loss of elastic recoil, while chronic bronchitis causes obstruction through mucus hypersecretion and airway inflammation.
Explain the underlying pathophysiology of asthma and how it leads to airway obstruction.
Bronchial hyperresponsiveness, airway inflammation, and reversible airway obstruction. Inflammatory cells such as eosinophils, mast cells, and lymphocytes damage the bronchial epithelium, causing airway swelling, mucus production, and bronchoconstriction, which narrow the airways and reduce airflow.
What laboratory criteria are used to diagnose diabetes mellitus using a fasting plasma glucose and hemoglobin A1C?
Fasting plasma glucose ≥126 mg/dL
Hemoglobin A1C ≥6.5%
Describe the primary pathophysiologic difference between type 1 and type 2 diabetes mellitus.
Explain how ventilation–perfusion (V/Q) mismatch contributes to hypoxemic respiratory failure, particularly in patients with advanced COPD.
V/Q mismatch occurs when areas of the lung are ventilated but not perfused, or perfused but not ventilated.
Describe the inheritance pattern of cystic fibrosis and explain how it affects disease development.
Cystic fibrosis is an autosomal recessive disorder caused by mutations in the CFTR gene. An individual must inherit two defective copies of the gene—one from each parent—to develop the disease.
Describe the role of T-helper 2 (Th2) cells in the pathogenesis of asthma.
Th2 cells stimulate IgE production, mast cell growth, and eosinophil activation. This immune response promotes chronic airway inflammation and bronchial hyperreactivity, contributing to asthma symptoms and airway remodeling over time.
Differentiate diabetic ketoacidosis (DKA) from hyperosmolar hyperglycemic state (HHS) in terms of pathophysiology and patient population.
Differentiate between hypoxemic respiratory failure caused by impaired diffusion and hypercapnic respiratory failure caused by hypoventilation.
Hypoxemic respiratory failure from impaired diffusion results in low oxygen levels without significant CO₂ retention, while hypercapnic respiratory failure results in elevated CO₂ due to inadequate ventilation.
Explain how CFTR gene mutations lead to thick, viscid mucus in cystic fibrosis.
Mutations in the CFTR gene impair chloride transport across epithelial cell membranes. This disrupts sodium and water movement, leading to dehydration of mucus, making it thick and sticky.
Discuss the typical pulmonary function test (PFT) findings seen in COPD and explain what these findings indicate about lung function.
COPD PFTs typically show decreased FEV₁, decreased FEV₁/FVC ratio, increased residual volume, and increased total lung capacity.