Which statement best describes athero?

• A. Plaque formation in arterial walls
• B. Hardening of arterial walls
• C. Dilation of veins
• D. Clot formation in veins

Answer: (A)

Atherosclerosis is the buildup of plaques inside arterial walls. This plaque consists of lipids, inflammatory cells, smooth muscle, and fibrous tissue, and it narrows the vessel while also making it stiffer. That plaque formation in the arterial walls is the defining feature of athero, and it explains why blood flow is restricted and the risk of plaque rupture leading to ischemia or embolic events.

Hardening of arterial walls describes arteriosclerosis, a related but broader process of stiffening that can occur with aging or other conditions; while atherosclerosis can contribute to stiffening, the key description of athero is plaque formation inside the arteries. Dilation of veins is a venous issue, not arterial plaque buildup, and clot formation in veins points to venous thrombosis, not atherosclerosis.