Asthma: The Respiratory System

Asthma is a disorder of the respiratory system that blocks the airway making it difficult to breath. It is described as a reversible inflammation of the respiratory system. It is characterized by obstruction of airflow, hypersensitivity, and inflammation. Asthma is prevalent more in children than in adults. The disease is estimated to be affecting more than 24 million people in the United States.
Symptoms of Asthma
Asthma is characterized by several symptoms most of which affect the components of the respiratory system. One of the key but not definitive symptoms is persistence coughing that tend to occur during the night. The coughing episodes sometimes can be triggered by laughing or exercise. Other symptoms include shortness of breath, wheezing, and chest tightness.
Causes and Risk Factors for Asthma
Asthma is triggered by allergens that can include pollen, infection, cold, and dust among others. The main risk factors for asthma include genetic composition, where one or more close family members have the condition. The other risk factor includes the presence of allergic conditions, for instance, atopic dermatitis or rhinitis. Obesity and either active or passive smoking can increase the odds of acquiring asthma.
Anatomy and Physiology of the Respiratory System
The respiratory system is one of the most critical systems in the human body. It is located within the thorax, and its main function is facilitating gaseous exchange. Air that contains oxygen is taking into the lungs while carbon dioxide is breathed out of the body. The respiratory system is composed of the lungs, diaphragm, upper and lower airways as well as other muscles of respiration. Upper airways are made of the larynx, pharynx, and nasal cavity. On the other hand, the lower airways consist of the trachea, bronchi, and bronchioles. The air travels to the lungs from the upper airway to the lower airway and eventually to the alveoli in the lung parenchyma. The airways are always patent in normal conditions and allow free air movement and exchange in the alveolus. The alveoli have a large surface area and are rich in blood supply. The surface area and blood supply increase the efficiency of gaseous exchange in the lungs and increase the supply of the blood with adequate oxygen for metabolic requirements. Besides, the surface of the alveoli is made up of a thin, moist layer that dissolve the air facilitating diffusion into the blood capillaries. The airways are made up of smooth muscles that play the role of adjusting the lumen of the pathway depending on the oxygen demands. The inner walls of the airways are also covered with mucous that moistens and warms the inhaled air.
Asthma Pathophysiology
Asthma occurs when the hypersensitivity airways are triggered by allergens such as pollen, cold, hay, smoke, or dust among others. The presence of allergens stimulates the body to produce Immunoglobulin E that activates mast cells. Mast cells produce histamine and other cytokines that facilitate inflammation of the airways, hyper secretion of mucous, and mucosal edema. These events lead to narrowing of the airways hence obstructing the normal smooth airflow to and from the lungs.
Asthma Diagnosis and Treatment
The best approach used in diagnosing asthma is by taking the comprehensive medical history of the patient, lung function test as well as clinical or physical examination. Asthma is managed by use of appropriate medication depending on the severity and age of the patient. Asthma as six treatment steps where the first step is mild sickness and the last step is a severe disease. The medications used to treat asthma include short-acting beta two agonists such as salbutamol and inhaled corticosteroids for instance budesonide. Other drugs include long-acting beta two agonists for example eformoterol, leukotriene receptor blockers such as montelukast and cromones. Cromones are mast cell stabilizers and include nedocromil sodium and sodium cromoglycate.
Definitions
Inflammation: It is the state whereby a part of the body becomes swollen, reddened, warm and sometimes painful.
Airways: The pathway through which air gets in or out of the lungs.
Hypersensitivity: Refers to undesirable reactions produced by the body’s immune system due to intolerance of some substances.
Allergen: A substance that triggers immune response resulting in hypersensitivity or allergic reactions.
Immunoglobulin E: It is a group of antibodies produced by the body’s immune system following exposure to an allergen.
References
Bislimi, A. H., & Tolka, L. C. (2012). Asthma: Causes, complications & treatment. Hauppauge, N.Y: Nova Science.
Sheen, B. (2011). Asthma. Detroit: Lucent Books.
Douglas, G., & Elward, K. S. (2011). Asthma. London: Manson.
In Calhoun, K. H. (2014). Asthma: Screening, diagnosis, and management. New York: Elsevier Health Sciences.
Lew, K. (2010). Respiratory system. Tarrytown, NY: Marshall Cavendish Benchmark.