The pathophysiology of pneumonia involves the following steps:
• Inhalation of Infectious Agents: Pneumonia typically begins when pathogenic organisms (bacteria, viruses, fungi) are inhaled or aspirated into the lower respiratory tract.
• Overcoming Lung Defenses: Ideally, the respiratory tract has defense mechanisms like mucociliary clearance and cough reflex to prevent the establishment of pathogenic organisms. If these defenses are compromised, or the pathogen is highly...