Question

Hand draw the Human Acute Myocardial Infarct, the cardiac muscle following an acute myocardial infarct and label the following structures: wavy cardiac muscle cells, pale area of infarct, normal cardiac muscle cells. Also draw Human Old Myocardial Infarct, the cardiac muscle after a long recovery from a myocardial infarct and label the following structures: fibrous tissue, normal cardiac muscle cells

Answer 1

There are 4 diagrams here_A&B shows acute changes of myocardial infarction,and C&D shows healed myocardial infarct.

A&C are histological diagrams and B&C are simplified forms of them respectively.

A&B shows changes such as coagulative necrosis and wavy fibres (structural changes due to necrosis).

Wavy fibres are elongated and narrow,as compared with normal myocardium as shown indiagrams.

Widened spaces in between dead fibres contain edema fluid and scattered neutrophils,hence pale area.

C&D shows healed myocardial infract_in which the necrotic tissue has been replaced by dense collagenous scar,the residual cardiac muscle cells show evidence of compansatory hypertrophy. Fibroblasts,lymphocytes and capillaries are seen.