The atheroma ("lump of porridge", from Athera,) is the nodular accumulation of a soft, flaky, yellowish material at the center of large plaques, composed of macrophages nearest the lumen of the artery, underlying areas of cholesterol crystals, and possibly also calcification at the outer base of older/more advanced lesions. The following terms are comparable, yet diverse, in …show more content…
Consequently, atherosclerosis is a type of arteriosclerosis. Arteriosclerosis ("hardening of the artery") results from a deposition of tough, rigid collagen inside the vessel wall and around the atheroma. This increases the stiffness, decreases the elasticity of the artery wall. Arteriolosclerosis (hardening of small arteries, the arterioles) is the product of collagen deposition, but also muscle wall thickening and deposition of protein ("hyaline"). Calcification, occasionally even ossification (formation of complete bone tissue) occurs within the deepest and oldest layers of the sclerosed vessel