What does the term "atelectasis" refer to?

Atelectasis refers to a collapse of part or all of a lung, resulting in impaired gas exchange. This condition occurs when the tiny air sacs (alveoli) within the lung become deflated or filled with fluid, preventing proper airflow and reducing the lung's effectiveness in oxygenating blood. It can arise from various causes such as obstruction of the air passages, pressure on the lungs from outside the lung tissue, or after surgery when deep breathing is limited.

Understanding atelectasis is crucial for respiratory health, as it can lead to complications like pneumonia if not addressed. Recognizing the signs and symptoms, such as shortness of breath or decreased oxygen saturation, is essential for effective management and treatment.

The other options refer to different respiratory conditions, which do not accurately define atelectasis. For example, an increase in lung volume relates to overinflation or conditions like hyperinflation seen in chronic obstructive pulmonary disease (COPD). Fluid accumulation in the lungs is indicative of pulmonary edema, and a spasm of the airways refers to bronchoconstriction, frequently associated with asthma. Each of these conditions involves different mechanisms and treatment approaches compared to atelectasis.