What respiratory disorder is caused by bacteria and viruses and produces inflammation of the lungs?

Pneumonia is an infection that leads to inflammation of the lungs, which can be caused by various pathogens, including bacteria and viruses. When these microorganisms invade the lung tissue, they trigger an immune response, leading to the accumulation of fluid and cells in the alveoli (the tiny air sacs in the lungs). This inflammation can impair gas exchange and cause symptoms like cough, fever, and difficulty breathing.

Other respiratory disorders, such as pleurisy, bronchitis, and asthma, involve different mechanisms and etiologies. Pleurisy is inflammation of the pleura, the membranes surrounding the lungs, usually caused by other underlying infections rather than being a primary infectious process. Bronchitis typically involves inflammation of the bronchial tubes and can be caused by viruses but is often a separate condition from pneumonia. Asthma is a chronic inflammatory condition that affects the airways, often triggered by environmental factors rather than infections directly.

Understanding that pneumonia specifically involves lung inflammation as a direct consequence of infectious agents clarifies why it is the correct answer in this context.