The Incredible Journey

2280 Words Apr 15th, 2009 10 Pages
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
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The Human Lungs
Our lungs are vital organs that fuel us with a life-sustaining gas: oxygen. They are also important to ensure survival. In this report, there will be information about the size, structure, function, and diseases/health problems of the human lungs.

The size of the human lungs varies due to gender, size of body, inheritance, and age. A common way to measure the size of the lungs is by total lung capacity (TLC), and the average TLC for a human adult is between 5.8-6L. The normal mass of an adult human lung is between 300-400g.

There are two lungs: the left lung, and the right lung. They are similar, and have a covering of two air-tight bags called the pleural sacs. The whole lungs are divided into lobes. The right lung has three lobes, and the left lung has two lobes. The right lung’s lobes are: the superior lobe, the inferior lobe, and the middle lobe. On the other hand, the left lung’s lobes include: the superior lobe, and the inferior lobe. In each lung, the inferior and superior lobe is separated by the oblique fissure, and, in the right lung, the superior and middle lobe is separated by the horizontal fissure.

The actual inside of a lung can be further divided into two zones. There is the conducting zone that consists of the main bronchi, the lobar bronchi, the segmental bronchi, the bronchioles, and the terminal bronchioles. There is also the respiratory zone, which is made up of the alveolar