Which condition allows air to enter the pleural cavity?

The condition that allows air to enter the pleural cavity is pneumothorax. Pneumothorax occurs when air leaks into the space between the lung and the chest wall, leading to a collapse of the lung on the affected side. This can happen due to trauma, a medical procedure, or can be spontaneous in nature. The presence of air in the pleural cavity disrupts the negative pressure that is necessary for the lungs to expand fully during inhalation, which can result in difficulty breathing and chest pain.

In contrast, pulmonary disease encompasses a broad range of conditions affecting the lungs but does not specifically refer to air entering the pleural cavity. Bronchitis, an inflammation of the bronchial tubes, generally involves excess mucus production and coughing rather than pleural cavity involvement. Asbestosis is a chronic lung disease caused by the inhalation of asbestos fibers and does not lead to air entering the pleural space. Therefore, pneumothorax is the specific condition that meets the criteria for allowing air into the pleural cavity.