2. Scope of Asthma
Now asthma is the most common chronic disease in children, affecting one in every 15 children. In North America, 5% of adults are also afflicted by asthma. In total, approximately 1 million Canadians and 15 million Americans who suffer from this disease.
Numbers of new cases and the annual rate of hospitalization for asthma have increased 30% over the past 20 years. Even with advances in treatment, deaths from asthma among young people has more than doubled.
The Normal Bronchial Tubes
Before we can assess how asthma affects the bronchial airways, we should first take a quick look at the structure and function of the bronchial tubes are normal.
The air we breathe in through the nose and mouth passes through the vocal cords / vocal cords (larynx) and windpipe into / windpipe (trachea). Then the air into the lungs through two large airways (bronchi), one for each lung. In each lung bronchi divide into the airways smaller and smaller (bronchioles), so like the branches of an inverted tree. Inhaled air is carried through the airways is the millions of tiny air sacs (alveoli) are contained in the lungs. Oxygen (O2) passes from the air sacs into the blood stream through the blood vessels which many called capillaries. In the same way, the body wastes, carbon dioxide (CO2), turned to the air sacs and then eliminated at each disposal breath.
Bronchial tubes that normally allow rapid passage of air into and out of the lungs to ensure that the levels of O2 and CO2 remained constant in the bloodstream. Outer walls of the bronchial tubes dikellingi by smooth muscles that contract and relax automatically with each breath. This allows the required amount of air to enter and exit the lungs in order to achieve this normal exchange of O2 and CO2. Contraction and relaxation of bronchial smooth muscles are controlled by two different nervous systems that work in harmony to keep the airways remain open.
The inner lining of the bronchial tubes, called the bronchial mucosa, contains: (1) mucous glands (mucous glands) that produce just enough mucus to lubricate the airways well, and (2) a variation of the so-called cell- inflammatory cells, such as cells eosinophils, lymphocytes, and mast. These cells are designed to protect the bronchial mucosa (bronchial mucosa) of the microorganisms, allergens, and spam-spam (irritants) that we breathe, and that can cause bronchial tissues swell. Remember, however, that these cells are inflamed it is also an important player in allergic reactions. Therefore, the presence of these cells in the bronchial tubes causing them a prime target for allergic inflammation.