Pathology MCQ4

Pathology MCQ4:
At autopsy, the heart of a 63-year-old man weighs only 250 g (normal 330 g) and has small right and left ventricles. The myocardium is firm, with a dark chocolate-brown colour throughout. The coronary arteries show minimal atherosclerotic changes. An excessive amount of which of the following substances, shown in the figure, would most likely be found in the myocardial fibers of this heart?

A Bilirubin
B Glycogen
C Hemosiderin
D Lipofuscin
E Melanin

Explanation:
Lipofuscin is a “wear-and-tear” pigment that increases with aging, particularly in liver and myocardium.This granular golden brown pigment seen adjacent to the myocyte nucleus in the figure has minimal effect on cellular function in most cases. Rarely, there is marked lipofuscin deposition in a small heart, a so-called brown atrophy.
Bilirubin, another breakdown product of hemoglobin, imparts a yellow appearance (icterus) to tissues. Hemosiderin
is the breakdown product of hemoglobin that contains the iron. Hearts with excessive iron deposition tend to be large. Glycogen is increased in some inherited enzyme disorders, and when the heart is involved, heart size increases. Melanin pigment is responsible for skin tone: the more melanin, the darker the skin.
So, the correct option is D(Lipofuscin).

(P. C :Science photo library)




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