Applied Biology Essay Example | Topics and Well Written Essays - 2000 words

Applied Biology - Essay Example This interruption of blood supply and thereby shortage in oxygen supply is normally caused by the collection of vulnerable atherosclerotic plaque, which is a combination of lipids and White Blood Cells, on the walls of the arteries. This plaque only results in ischemia, and will lead to minimal or extensive infraction or death of the myocardial cells in the heart. When this myocardial infraction happens, the structure and the function of the heart undergo sizable changes. Following myocardial infarction, there will ischemic cascade during which the affected cells will die. Then, the leukocytes and the fibroblasts start to migrate into that necrotic region, and so the death tissue gradually remodels into a dense collagenous scar. (Ingels, Daughters and Baan 1996). In addition, the damages that happen in the myocytes and extracellular matrix formation after myocardial infarction, changes the size and the shape of the left ventricle and heart, thus impacting its structure. This process of changes is commonly known as â€Å"myocardial remodeling†. (Davis, Davies and Lip 2007). During that process of remodeling, the remaining functioning cells of the heart tries assume a different shape by enlarging itself and this is known as hypertrophy. By attaining this enlarged shape, those muscles will try to counter and manage the loss of synchronicity in the functioning of the muscles. These structural changes happen automatically, so the heart can compensate for the loss of key heart muscles. Thus, the function of the heart also gets reoriented after myocardial infraction, because its efficiency deteriorates due to the inability of the dead myocardial cells to aptly contract and thereby contribute to the heart beat and functioning. Even when the heart cells enlarge to compensate for the dead cells, it may not have the desired effect. That is, the enlarged cells may not be able to contract as forcefully and as effectively as the normal-sized and normal functioning cel ls. This restricted function will directly hinder the heart’s ability to generate expectant force during each beat or contraction, thus limiting heart’s functioning and its’ pumping of blood for all parts of the body. In addition, the function of the electrical system of the heart, which initiates the signals for a contraction, could also get disturbed because of the changes in the structure of the heart after myocardial infraction. The disturbance will be in the form of irregular heart rhythms, which is known as arrhythmias, which is a serious and restrictive problem, and has to be treated through medication or through permanent pacemaker implantation. The structural changes could also activate â€Å"systemic processes causing sequelae in many other organs and tissues, as well as further damage to the heart.† (Davis, Davies and Lip 2007, p.10). Thus, these changes in the structure and the function of the heart happens in the form of a vicious cycle, lead ing to further deterioration of the heart, causing other serious complications, which includes total heart failure. 2. Heart failure is a possible complication of a myocardial infarction. Describe the signs/symptoms and explain the physiological changes that are causing them. Heart failure can be categorized and arbitrarily divided into Left-sided failure and Right-sided failure, with each exhibiting certain symptoms. However, Left sided forward failure could overlap with the right sided backward failure, and also importantly the right-sided heart failure could be caused by the left-sided heart failure. Thus, as both are interrelated, the patients could present with both sets of symptoms. Person being affected with heart failure could exhibit mainly the symptoms of shortness of breath and swelling,