The Incredible Journey

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The Human Heart
The human heart is one of the most important organs in our bodies. However, it is basically a muscular structure that pumps blood. In this report, there will be information on the size, structure, function, and diseases/health problems of the human heart.

The size of the human heart varies due to factors such as gender, size of the body, inheritance, and age. However, a normal size of a person’s heart is about the same size as his/her clenched fist (9cmx13cm), and has a mass between 250-350g (approximately 300g).

The human heart has three-layered walls and four cavity areas. The layers of the walls consist of: the epicardium (outer layer), the myocardium (middle layer), and the endocardium (inner layer). The wall that separates the two halves of the heart is called the septum. The left half of the heart is smaller, but has thicker walls than the right half. This is because it needs to have more force to pump the blood at greater distances than the right half. The heart also has four cavity areas. They are the right atrium, the right ventricle, the left atrium, and the left ventricle. The atria are at the top half in both sides of the heart, and the ventricles are at the bottom half of the heart.

In addition to wall and the cavity areas, the heart has blood vessels that are connected to the heart. They include: the two vena cavas, which are connected to the right atrium, the pulmonary arteries, which are connected to the right ventricle, the pulmonary veins, which are connected to the left atrium, and the aorta, which is connected to the left ventricle.

The last part of the heart is the heart valves. Some of them come in pairs, and they are: the atrioventricular valves, and the semilunar valves. The two atrioventricular valves, which separate the atria and the ventricles in both sides of the heart, are called the right atrioventricular (tricuspid) valve and the left atrioventricular (mistral) valve. The two other semilunar valves are the aortic valve, which lies between the ventricle and the aorta, and the pulmonary valve, which lies between the right ventricle and the pulmonary arteries. Adding to that, there are also two separate valves called the valve of coronary sinus and the valve of inferior vena cava.

Literally, the heart carries out one function: to pump blood around the body. The right atrium receives deoxygenated blood through the superior vena cava, the inferior vena cava, and from the heart muscle itself through the coronary sinus. After the blood occupies the atrium, the tricuspid valve is opened, which only allows the blood to flow in the direction from the atria to the ventricle. The right ventricle then pumps the blood through the pulmonary valves, and into the pulmonary arteries, which lead to the lungs. Soon, the left atrium receives the blood from the lungs through the pulmonary veins, and opens up the mistral valve. The fluid then moves into the left ventricle, and is pumped throughout the body through the aortic valve and along the aorta. After some time, the blood reaches the vena cavas, and this cycle restarts.

There are many types of heart diseases. Some common ones are: coronary heart disease stroke, rhythmic heart disease, heart failure, and valvular heart disease.  Some causes of heart diseases include: congenital defects, infection, narrowing of the coronary arteries, and disturbances. There are a few ways to prevent heart diseases, and they are: exercise, eating healthy foods, avoiding drugs, and getting regular checks with heart experts. Different types of heart diseases have different symptoms, which include: chest pain, shortness of breath, weakness and fatigue, palpitations, lightheadedness, and fainting. In fact, some forms of heart disease do not have any symptoms at all during early stages. There are different types of treatments for different types of blood diseases. For example, some common treatments include: medications, procedures and surgeries, and...
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