There are many people that suffer from asthma who vary in age, weight, gender, and race. Although the exact cause of asthma is unknown, researchers have been able to pinpoint environmental and non-environmental irritants that can cause asthma. Some people are at a genetic predisposition, while others experience asthma when under stress and anxiety. Both irritants trigger an immune response within the lungs leading to symptoms of asthma.
Asthma is a chronic disease caused by inflammation of the airways of the lungs. It affects the respiratory system which contains the organs necessary for gas exchange; delivering oxygen to the blood and releasing carbon dioxide into the environment. During respiration, oxygen travels down the trachea which branches out to more airways in the lungs, called bronchi. Bronchi continue to branch out into even smaller airways called bronchioles. At the end of the bronchioles are air sacs called alveoli, which is where gas exchange occurs. Figure 1 depicts the pathway of airflow to the lungs.
How Does Asthma Change the Lung Structure and Effect the Body?
In a patient without asthma, oxygen is delivered smoothly; air flows in and out of the body and the patient can breathe normally. However, in a patient with asthma, several environmental factors (such as allergens and aerosols) and non-environmental factors (such as genetic factors and stress) can cause irritation and trigger an immunity response within the bronchi and bronchioles of the lungs. Immunity cells, such as eosinophils and mast cells, begin producing a chemical mediator called leukotriene. Leukotriene is responsible inflammation, vascular dilation, and increasing vascular permeability and production of mucus.It also mediates other immunity cells to the area, causing an overproduction of leukotriene, resulting in more inflammation and mucus production. When the smooth muscle of the bronchi and bronchioles become inflamed the muscles begin to constrict. These constrictions are called bronchospasms, and make it difficult for oxygen to be passed through the lungs. This is followed by a number of symptoms including coughing, wheezing, shortness of breath and chest tightness (American Academy of Asthma Allergens Immunology (AAAI), 2012; Cloe, 2007, The Asthma and Allergy Center, 2011). Figure 2 depicts the changes in the bronchioles in response to asthma.
Treatment of Asthma
Unfortunately there is no cure for asthma, but the use of inhalers is the primary treatment for asthma. Several types of inhalers help treat asthma and include metered-dose inhalers, metered-dose inhalers with spacer, and dry powder inhalers.
- American Academy of Asthma Allergens Immunology (AAAI). (2012). Asthma. Retrieved from http://www.aaaai.org/conditions-and-treatments/asthma.aspx
- Cloe, A. (2007, October 27). The role of leukotrienes in asthma. Retrieved from http://www.livestrong.com/article/22472-role-leukotrienes-asthma/
- The Asthma and Allergy Center. (2011). Leukotrienes' role in asthma . Retrieved from http://www.asthmaandallergycenter.com/w/asthma.mvc/Details/36
- Mayo Foundation for Medical Education and Research. (Artist). (n.d.). Airways and air sacs of the lungs. [Print Graphic]. Retrieved from https://www.lumigenix.com/results/content/DS00038/Causes/0
- A.D.A.M. (Artist). (2009). Normal versus asthmatic bronchiole. [Print Photo]. Retrieved from http://www.umm.edu/patiented/articles/000556.htm