Final answer:
Atherosclerosis is the condition where artery walls thicken and stiffen due to the buildup of fatty plaques inside the arteries, leading to narrowing of the arteries and reduced blood flow.
Step-by-step explanation:
Atherosclerosis is a condition in which artery walls thicken and stiffen due to the buildup of plaques inside the arteries. Plaques consist of white blood cells, cholesterol, and other fats. These fatty plaques can narrow the arteries, reducing blood flow. Over time, the plaques may harden with the addition of calcium crystals, further reducing the elasticity of the artery walls.