Which condition occurs when a tear in the inner wall of the aorta causes blood to flow between layers of the wall?

• A. Aneurysm
• B. Aortic dissection
• C. Atherosclerosis
• D. Cardiomyopathy

Answer: (B)

A tear in the inner wall of the aorta with blood dissecting between wall layers is an aortic dissection. This happens when the intima, the innermost layer, is breached and high-pressure blood enters the wall, splitting the media and creating a false channel alongside the true lumen. It’s an emergency because the dissection can extend and compromise blood flow to organs or rupture. This exact mechanism—blood entering and separating the layers of the aortic wall—defines dissection.

In contrast, an aneurysm is a dilation or ballooning of a vessel wall, not a split between layers. Atherosclerosis involves plaque buildup inside arteries, leading to narrowing or blockage, not a dissection. Cardiomyopathy is a disease of the heart muscle itself, affecting its function rather than the integrity of the aorta’s wall.