Which term is defined as blood clot blocking the pulmonary artery?

• A. Spontaneous Pneumothorax
• B. Pleural Space
• C. Pulmonary Embolism
• D. Oxygen Therapy

Answer: (C)

A clot blocking the pulmonary artery is called a pulmonary embolism. It happens when a thrombus—often that starts in a deep vein of the leg—travels through the veins, reaches the right heart, and lodges in the pulmonary arteries. That blockage stops blood from reaching portions of the lung, leading to a mismatch between ventilation and perfusion and reduced oxygen in the blood. Clinically, this condition can present with sudden shortness of breath and chest pain and can vary in severity depending on the size and location of the blockage.

The other terms refer to different issues: spontaneous pneumothorax is air in the pleural space causing the lung to collapse, the pleural space is the thin potential space around the lungs, and oxygen therapy is a treatment used to improve oxygen levels rather than a condition itself.