Human Anatomy: Heart Disease - Research Paper Example

Human Anatomy: Heart Disease Introduction Human heart is a muscular organ which is also the most vital element in the human body. It functions as the blood pumping station that ensures continuous blood circulation through the cardiac circle. Since heart is the vital and sole organ that pumps blood throughout the body cells, its failure will cause death. The rampant increase in the number of heart patients can be attributed to the changing life styles and food habits. This paper will discuss the overall anatomy of the heart and the path of blood flow. It will also evaluate anatomical cardiovascular concepts to get an idea about heart diseases. Overall anatomy of the heart An average human heart weighs between 7 and 15 ounces (200 to 425 grams) and it is almost as large as the human fist. By the end of an average person’s life, his heart would beat (expanded and contracted) more than 3.5 million times. Each day, an average heart beats nearly 100,000 times by pumping around 2,000 gallons (7,571 liters) of blood. The human heart is located between lungs and middle of the chest. Pericardium is the double-layered membrane that surrounds the heart as a sac. In between the two membranes of the pericardium, there is a coating fluid that protects the heart from external shocks and overfilling of blood. The inner layer of the pericardium, which is a smooth lubricated sliding surface, enables the heart organ to easily move in response to its own contractions and expansions. Three layers constitute the outer wall of the human heart. The outermost layer is called epicardium as it also acts as the inner wall of the pericardium. Myocardium is the middle layer of the heart; the inner layer is called endocardium which is in contact with the blood that flows through the heart. Human heart has four chambers; the upper chambers are called left and right atria while left and right ventricles constitute the lower chambers. The left ventricle is the largest as well as strongest chamber in the heart. There are four types of valves such as tricuspid valve, pulmonary valve, mitral valve, and aortic valve present in the human heart, which regulates blood flow through the heart. Path of blood flow through the heart The direction of blood flow through the heart is from atria to ventricles; the backward flow of blood through the heart is prevented by the four valves. In the circulatory system, heart acts as a double pump. Both inferior and superior vena cavae collect deoxygenated blood respectively form inferior and superior part of the body and passes it to the right atrium. The right atrium pumps the impure blood to the right ventricle and the tricuspid valve regulates the flow of blood between these two chambers. From the right ventricle, the deoxygenated blood is carried to lungs through pulmonary arteries. Chiras (2010, p.135) describes that purification of blood takes place at the lungs where the impure blood drops off carbon dioxide and picks up oxygen; this process is called gas exchange. The passive process of diffusion assists this gas exchange action. The pulmonary valve blocks the backward blood flow from pulmonary arteries to right ventricle. The pulmonary veins carry the oxygenated blood from the lungs to left atrium. From the left atrium, the oxygenated blood is pumped to left ventricles; the mitral valve allows the oxygen rich blood to pass from the left atrium to left ventricle. The left ventricle, the strongest chamber of the heart, pumps the oxygenated blood to the rest of the body through aorta. The vigorous contractions of the left ventricle constitute the blood pressure. The aortic valve, which is situated at the opening of aorta, regulates the pumping of blood form the left ventricle to aorta. There are coronary arteries across the surface of the heart and it supply oxygenated blood to heart muscle. A network of nerve tissues also runs through the heart and it conducts the complex signals which regulate the processes of contraction and relaxation. The flow of blood to and from the heart is a cyclical process and it continues restlessly even when we are resting. Atherosclerosis As Ambrosioni, Bacchelli, Esposti, and Borghi point out, atherosclerosis is a type of cardiovascular disease is usually caused by the thickening of an artery wall due to the accumulation of fatty materials. Atherosclerosis is a type of arteriosclerosis and they are often termed interchangeably. Atherosclerosis is a common disease found in modern days, which primarily affects medium and large arteries. The fatty materials harden the artery walls and gradually block the arteries. The block is occurred when the accumulated fat substances form a structure called plaques. Arteries must be flexible so that it can expand and pass blood to various part of the body when the left ventricle pumps the oxygenated blood. The blood pumping mechanism of the heart would not be effective if the artery walls are thickened. According to Bihari-Varga, Kostner, and Czinner, if plaques are formed at the wall of coronary arteries, blood flow to the heart may slow down or stop. This condition may cause heart attack, chest pain, shortness of breath and other symptoms. Sometimes, the formed plaque may break off and the broken pieces would move through artery to small blood vessels; it would certainly block the blood circulation and may lead to tissue damages or embolization. Atherosclerosis is a common cause of heart attack and stroke. Blood clots may also form in the artery walls leading to a block in blood circulation. If the formed clot moves to lungs, brain, or coronary arteries, it would cause heart attack, stroke, or pulmonary embolism. Diabetes, heavy alcohol use, obesity, high blood pressure, high fat diet, smoking and high blood cholesterol levels are some of the risk factors for atherosclerosis. Symptoms of this disease would not appear until the blood flow becomes completely blocked. Coronary artery disease, hypertension, stroke, kidney disease, and abdominal aortic aneurysm are the major symptoms of this disease. Conclusion In total, heart is the most vital human organ that has the potential to operate relentlessly since birth to death. The heart consists of four chambers among which, right chambers of the heart carry deoxygenated or impure blood whereas purified and oxygen rich blood is collected in left chambers of the heart. The four valves in the heart effectively regulate the circulation of the blood. Atherosclerosis is a cardiovascular disease which is caused by the accumulation of fatty materials at the walls of the artery. Works Cited Ambrosioni, E. Bacchelli, S. Esposti, D and Borghi, C. “ACE- Inhibitors and atherosclerosis”, European Journal of Epidemiology, 1992. 8: 129-133. Bihari-Varga, M. Kostner, G and Czinner, A. “Lp(a) and the risk of coronary heart disease”. European Journal of Epidemiology, 1992, 8: 33-35 Chiras, Daniel D. Human Biology. US: Jones & Bartlett Learning, 2010. Print. Read More