Lung Cancer essays

Lung Cancer essays The lungs are two sponge-like organs found in the chest cavity. The right lung has three sections, called lobes. The left lung has two lobes. It is smaller because the heart takes up more room on that side of the body. The lungs bring air in and out, taking in oxygen and getting rid of carbon dioxide gas, a waste product of the body. The lining that surrounds the lungs and helps to protect them and to facilitate the sliding motion during breathing is called the pleura. The chest cavity is called the pleural cavity. The windpipe brings air down into the lungs. It divides into tubes called the bronchi, which divide into smaller branches called the bronchioles. At the end of the bronchioles are tiny air sacs known as alveoli. Most lung cancers start in the lining of the bronchi. Less often, cancers begin in the trachea, bronchioles, or alveoli. Lung cancers are thought to develop over a period of many years. First, there may be areas of cancerous changes in the lung. These changes do no t form a mass or tumor. They cannot be seen on an x-ray and they do not cause symptoms. But, researchers are studying new tests to detect cancerous changes by analysis of cells in sputum and by viewing the lining of the airways through a bronchoscope. If these cancerous changes progress to true cancer, malignant cells begin to grow. The cancer cells may produce chemicals that cause new blood vessels to form nearby. These new blood vessels nourish the cancer cells which can continue to grow and form a tumor large enough to see on x-rays. Cells from the cancer can break away from the original tumor and spread to other parts of the body. This process is called metastasis. Lung cancer is a life-threatening disease because it often spreads in this way even before it is detected by x-rays. Lung cancer is usually divided into two major types. The first type is small cell lung cancer (SCLC). The second type is non-smal ...