<prompt> Which pigment accumulates in brown atrophy of hea?MelaninLipofuscinHemosiderinHemozoin  <response>: Lipofuscin, or wear-and-tear pigment, is an insoluble brownish-yellow granular intracellular material that accumulates in a variety of tissues paicularly the hea, liver, and brain as a function of age or atrophy.Lipofuscin represents complexes of lipid and protein that derive from the free radical-catalyzed peroxidation of polyunsaturated lipids of subcellular membranes. It is not injurious to the cell but is a marker of past free radical injury. The brown pigment, when present in large amounts, impas an appearance to the tissue that is called brown atrophy. Melanin is an endogenous, brown-black pigment that is synthesized by melanocytes and acts as a screen against harmful ultraviolet radiation.Hemosiderin is a hemoglobin-derived granular pigment that is golden yellow to brown and accumulates in tissues when there is a local or systemic excess of iron. Robbins Basic Pathology, 9th edition, page 24 