American Board of Medicolegal Death Investigators (ABMDI) Practice Exam

Why is a pulmonary embolus referred to by this name?

1. It narrows the outlet of the right ventricle

2. It originates in the pulmonary artery

3. It occludes the pulmonary artery

4. It causes cherry pink livor mortis

The correct answer is: It occludes the pulmonary artery

A pulmonary embolus is referred to by this name because it specifically occludes the pulmonary artery. This condition occurs when a blood clot, often originating from the deep veins of the legs (deep vein thrombosis), travels through the bloodstream and lodges itself in the pulmonary artery. The blockage prevents blood from flowing properly to the lungs, leading to impaired gas exchange and potentially serious consequences for the patient, such as hypoxia or even death if not treated promptly. The other options relate to aspects of heart function and mortuary changes but do not accurately define what a pulmonary embolus is or its primary effect. For instance, while a pulmonary embolus does indeed impact the right ventricle as it obstructs blood flow, this does not encompass the reason for its specific naming. Similarly, while it's true that the origin of the embolus is often related to venous thrombosis, the term "pulmonary embolus" is fundamentally defined by its blockage of the pulmonary artery rather than its origin or secondary effects like livor mortis.