American Board of Pathology (ABPath) Practice Test

The correct choice focuses on the media, which is the middle layer of the vessel wall, consisting primarily of smooth muscle cells and elastic fibers. This layer plays a crucial role in maintaining the structural integrity and resilience of the artery. In cases of artery dissection, the media becomes weakened due to several factors, including hypertension, genetic disorders like Marfan syndrome, or degenerative diseases.

When the media is compromised, it can lead to the forming of a false lumen where blood accumulates between the layers of the arterial wall. This complicates blood flow and can ultimately cause various cardiovascular issues, including significant complications if not promptly addressed.

While the intima, adventitia, and endothelium are important for vascular health and function, they do not typically contribute directly to the occurrence of artery dissection. The intima, for example, is more involved in the regulation of blood flow and the prevention of thrombosis, the adventitia serves as a protective outer layer, and the endothelium lines the inside of the blood vessels, mediating exchanges between the blood and surrounding tissues. Thus, the media's weakness is the essential factor leading to arterial dissection.