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the heart

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Introduction

The heart Intro: The heart is a muscular organ and is responsible fore pumping blood around the body, and on average the human heart beats at 72 beats per minute. When looking at the heart (see diagram) it is important to remember that the left and right side are reversed (due to the way we are looking at it). The right side of the heart deals with deoxygenated blood and pumps it into the lungs. The left side of the heart deals with oxygenated blood, and pumps it around the entire body. The lower chambers of the heart is know as the ventricles and is more muscular and stronger than the upper chambers, known as the atria. This is because a large volume of blood is pumped from the ventricles up through the atria and around the body. It is important to maintain a healthy heart, as it reduces the risk of developing high blood pressure and cholesterol levels, as well as developing heart disease. By eating healthy and doing regular exercise we are able to reduce theses factors as well as reducing stress levels too. Main: The heart is a muscular organ that it part of the cardiovascular system. ...read more.

Middle

The valves snap shut to prevent any back flow of the blood. When the right ventricle contracts, it forces the blood through the semi lunar valve into the pulmonary arteries, and into the lungs. This is where gaseous exchange takes place, the deoxygenated blood has carbon dioxide removed by the expelling of the lungs, also known as respiration, and the blood is re-absorbed with oxygen. The heart contains four very important valves, the aortic, tricuspid, mitral and pulmonic valve. They ensure that the blood flows through the heart and body in one circuit, preventing any backflow. However, instead of the valves snapping shut, they can partially close, causing blood to flow back through to the chambers. This is known as having a leaky valve or a heart murmur. If this occurs it results in the heart being less efficient, by not allowing all the blood flow around the body. By using a stethoscope, you are able to hear the opening and snapping shut of the valves, commonly heard as being heard as lub dub. Our blood pressure is caused by the contraction of the heart and muscles that surround the blood vessels. ...read more.

Conclusion

Those who exercise more often and vigorously have a lower risk for heart disease. (healthcentral.com). The British Heart Foundation (BHF) states that by exercising we are able to control the previous risks, along with the combination exercise, should come healthy eating. This means eating five or more portions of fruit and vegetables per day, reducing the intake of fats, eating at least 2 portions of fish a week, and avoiding any extra added salt to food. According to new research funded by the British Heart Foundation and published in the Journal of the American College of Cardiology (JACC), poor health habbits are a key factor to those suffering from stress, which can result in an increased risk of heart disease. Stress is does not have a direct link with heart disease, but is known to have symptoms which may lead to it or contribute to it. For example, smoking, drinking alcohol or overeating are common ways to releive stress, but are likely factors that can lead to heart problems sooner or later. By learing how to relax, regular exercise and avoiding stressful situations it can reduce any symptoms which may lead to heart disease, such as angina. Conclusion: REFERENCE: http://www.healthcentral.com/diet-exercise/exercise-000029_3-145.html http://www.wikipedia.co.uk Diagram 1: http://chickscope.beckman.uiuc.edu/explore/embryology/day02/graphics/human_heart.jpg Diagram 2: http://www.infomat.net/infomat/focus/health/health_curriculum/images/heart.gif Diagram 3: http://www.heart-valve-surgery.com/heart-surgery-blog/2007/09/10/most-commonly-operated-on-heart-valve/ Diagram 4: ...read more.

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Response to the question

The candidate uses their introduction to mention basic facts about the heart, this would work better as secondary paragraph. An introduction should summarise what you plan to discuss. It sets the tone for the whole essay, and therefore gives you ...

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Response to the question

The candidate uses their introduction to mention basic facts about the heart, this would work better as secondary paragraph. An introduction should summarise what you plan to discuss. It sets the tone for the whole essay, and therefore gives you a chance to catch the reader’s attention. The candidate also repeats themselves a little in the second and third paragraphs, when writing an essay you should proof read your work and omit any repetitive sentences. It is pointless to say the same thing twice. On the other hand the candidate attempts to go into a suitable level of detail when describing the function of the heart’s chambers and valves.

Level of analysis

This essay starts well and the candidate has clearly tired to be very thorough and has attempted to cover all angles, however as the essay progresses I feel that detail is lost. For example s/he mentions the way in which blood is returned to the heart including the veins and valves used, yet they fail to mention how blood leaves the heart to be pumped around the body. For the most part there is good level of analysis in this essay and the candidate has undergone some independent research. It is clear that they have studied the risks linked with heart disease, though I think they could have elaborated on this and mentioned some of the different heart conditions. For example how these cause damage and the particular risks associated which each. S/he also mentions the way in which other parts of the body link with the cardiovascular system, such as the regulation of hormones carried out by the endocrine system. This additional knowledge shows the candidate’s interest in their subject and makes the essay more enjoyable to read. However it would have been appropriate to mention the way in which the heart beat is initiated, which would have shown a greater array of knowledge. Incidentally the candidate has included links to web pages in the fifth paragraph but it is not clear why they have done this. If you use web sources as guidance for writing an essay, then you do need to credit them. However the way is which this is done is in the form of a bibliography at the end of the essay, in which you list web pages you have used and provide a link to the source. Finally the candidate fails to conclude this piece of work, a conclusion is necessary in an essay, it allows you to draw your work to a close and end on a suitable point, without a conclusion the essay just stops and the reader can often be left feeling confused. A good conclusion needs to summaries your key points.

Quality of writing

The essay flows reasonably well and with the addition of a conclusion and a more suitable introduction this would be a well structured essay. I feel that or this level of qualification the candidate uses only an average range of vocabulary, however they use scientific terms appropriately. There is no real issue with spelling and grammar, however there is an occasional typing error, for example words have sometimes been omitted and sometimes a plural is used inappropriately, these could have been avoided if the candidate had proof read their work. Overall I would expect a more exceptional essay at this level, the essay doesn’t have a proper structure, and the candidate has made some silly errors. The candidate has undergone independent research, however they don’t quite go into enough detail on some of the simpler facts that you learn in A-level Biology.


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