Breathing is a vital process for every human. Normal breathing is practically effortless for most people, but those with asthma face a great challenge. During an asthma attack, breathing is hampered, making it difficult or even impossible for air to flow through the lungs. Asthma is an increasingly common problem, and has become the most common chronic childhood disease. At least 17 million Americans suffer from it(1), and although it can be fatal, it is usually not that severe(4). There is no cure for asthma, but with proper care, it can usually be controlled.
As someone with Exercise Induced Asthma, I have personal experience with the topic. I have experienced most of the symptoms described in my research, tried many of the medicines, and have my asthma under control. This essay will first discuss the normal function of the lungs, and then proceed to explain how this is effected by asthma. The causes of the disease and the ways of controlling it will follow.
Normal breathing is controlled by the lungs and the chest cavity. Airways are tubes with muscle that contracts and relaxes wrapped around them, and this accounts for the motion of the chest that is associated with breathing. The diaphragm, which is located underneath the rib cage, along with the intercostal muscles, or those in between the ribs, control the movement of the chest cavity(6). When these muscles contract, the chest expands, which lowers the pressure inside the lungs. Since air moves naturally from high to low pressure, the lungs are automatically inflated. In order to exhale, the diaphragm and the intercostal muscles relax, causing the chest cavity to become smaller. The decrease in volume causes the pressure in the lungs to go up, forcing the air out into the lower pressured atmosphere.
When air enters one's mouth or nasal cavity, it moves through the trachea, or the tube that connects the mouth to the lungs (6). It is also often referred to as the "windpipe." The trachea then branches off like a tree. The first splits of this "tree" are the bronchi, and the smallest branches are called the bronchioles. Thus after air travels through the trachea, it then reaches the bronchi, and spreads throughout the bronchioles.
Small air sacks called alveoli are at the tips of the bronchioles. When air reaches them, the oxygen concentration is high, which causes diffusion into red blood cells travelling through pulmonary capillaries (7). The red blood cells then distribute the new oxygen to the rest of the body. When they reach the alveoli again, they exchange carbon dioxide (a form of cell waste) for new oxygen, and repeat the process. The carbon dioxide is moved through the bronchioles, bronchi, and trachea in the form of exhalation.
The bronchi and bronchiole tubes are loosely wrapped with muscle. During regular breathing, the muscles around these airways are relaxed (5). This allows air to flow freely through these...