Assignment 2: Discussion Question

Most myocardial infarcts emanate from various complications in an individual’s coronary atherosclerosis. Atherosclerotic plaques can rupture their delicate fibrous caps or develop surface erosions that expose arterial blood to issues such as blood clotting or blood thrombosis. This results to deficiency or reduced blood flow into the heart muscle or myocardial ischemia(Tomanek, 2013). The myocardium has exceedingly high metabolic demands, therefore, if blood flow ceases one can experience irreversible damage to the tissue with a little time. In the process, cell death occurs over time starting with the innermost layer or sub endocardium and progressing on to the outer layer or subepicardium. Heart muscles have minimal intrinsic regenerative abilities and therefore at times they are irreplaceable. After the death of heart muscle cells a healing process normally ensues. This happens when white blood cells start digesting all dead muscle tissues. Afterwards, a provisional repair tissue known as granulation tissue replaces the digested tissue.

Cell injury can be defined as the alteration of a cell structure or its biochemical functioning that emanates from stress that surpasses its ability to recover through various physiological adaptive mechanisms. There are many types of cell injury and they can be either reversible or irreversible. Reversible cell injury is used to denote pathological cell changes that can be reversed if the stimulus is eliminated and the injury was mild. It can include ribosomes detachment from granular, cell swelling and polysomes dissociation into monosomes. Irreversible cell injury refers to pathological cell changes, which are entirely permanent and normally result to cell death(Tomanek, 2013). Irreversible cell injuries can include lysosomes swelling, mitochondria swelling and damages to the plasma membrane.

Both these two types of cell injuries result from the alteration of homeostasis. In the case of myocardial infraction if the blood supply is cut off for 15-20 minutes the myocardial cells will experience minimal injury but can recover. However, if the blood deficiency persists over a longer period then one experiences heart cells death. In Mr. Smith’s case he is experiencing irreversible cell injury since the heart cells are already dead and as discussed before they can only be replaced by a granular tissue which is not the same as the preexisting heart muscle tissue.


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