Which blood vessel is most likely to be blocked if a thrombus becomes dislodged?

The pulmonary artery is the most likely blood vessel to be blocked if a thrombus becomes dislodged due to the nature of blood flow and the common occurrence of thromboembolic events. When a thrombus dislodges, it typically travels through the venous system to the right side of the heart and then into the pulmonary circulation. This can lead to a pulmonary embolism, which occurs when the thrombus obstructs blood flow in the pulmonary artery, thereby affecting gas exchange and potentially causing severe respiratory distress.

In contrast, while thrombi can indeed dislodge and affect other arteries like the coronary or femoral arteries, the pulmonary artery is especially vulnerable due to its connection with the venous system and the prevalence of deep vein thrombosis (DVT) that can migrate. Understanding this mechanism emphasizes the critical nature of monitoring patients for signs of thromboembolic complications after surgeries or in cases of prolonged immobility.