Final answer:
Atherosclerosis is a condition where artery walls thicken and stiffen due to plaque buildup inside the arteries. This plaque is made of white blood cells, cholesterol, and fats. The presence of calcium crystals can also make the plaques harden, reducing the elasticity of the artery walls.
Step-by-step explanation:
Atherosclerosis is a condition in which artery walls thicken and stiffen as a result of the buildup of plaques inside the arteries. Plaques consist of white blood cells, cholesterol, and other fats. Over time, the plaques may harden with the addition of calcium crystals, reducing the elasticity of the artery walls.