Respiratory System Functioning - Essay Example

Respiratory System Human body is composed of different systems which work in conjunction with each other to maintain normal homeostasis in the body. These systems include: cardiovascular system which constitutes the heart and blood vessels, Urinary system which includes the kidneys, ureters and urinary bladder, Gastrointestinal system which is the main digestive system and the respiratory system starting from the external nares to the lungs. All these systems work in coordination with each other to keep the human body alive and functioning. A defect in any of these would lead to devastating consequences for the human body and may even cause death of the affected individual. Respiratory system is responsible for the oxygen supply to the body and removal of carbon dioxide from it. It starts from external nares in the nose and consists of larynx, pharynx which continues to form trachea. The trachea then divides into two main bronchi which further subdivide into bronchioles. Bronchioles continue to their smaller branches with in the lungs and end up alveoli supplying all the alveoli of the lungs. The vital and functional organs of the respiratory system are two lungs situated in the thoracic cavity just above the diaphragm and protected by the rib cage. The two lungs are further subdivided into lobes i.e. one lung has two lobes and the other has three making it larger than the other. (Davies, 2003) The main function of respiratory system is the exchange of gases between the human body and the outer environment. With each breath, oxygen is taken in and carbon dioxide is expired out. Air enters the body through external nares in the nose where it is warmed and moistened and then through the trachea it is transferred to the lungs where main exchange of gases takes place at the level of alveoli. The alveoli also known as the functional unit of lungs are small air sacs separated from each other by thin alveolar walls. The alveolar walls contain numerous capillaries that contain deoxygenated blood (Davies, 2003). The deoxygenated blood carrying carbon dioxide is pumped by the right ventricle into the lungs which contain air rich in oxygen. The exchange of gases takes place between the blood and alveoli and the alveolar wall as well as capillary membrane act as small barriers to limit this exchange. Oxygen is transferred to the blood from the lungs to the blood whereas carbon dioxide from the blood is transferred to the lungs which then expires it out. The process of inspiration and expiration is a tightly regulated mechanism. An average human being takes 12-24 breaths in a minute and this process is regulated by the central nervous system. The muscles that are used to contract (for expiration) and relax (for inspiration) the lungs include the diaphragm and the inter-costal muscles mainly. Any blockade or defect in the respirator pathway can prove to be fatal for the body since no organ in the human body can survive without a continuous supply of oxygen. Brain stops functioning within seconds after the supply is ceased and longer durations may cause irreversible damage to many other organs such as heart as well. Asthma is one of the most common inherited disorder of the respiratory pathway. It is defined as an autoimmune/hypersensitive response of the body to certain allergens leading to constriction of the bronchi and bronchioles and dyspnea. Asthma is usually type 1 hypersensitivity response to allergen. It is triggered when an allergen enters the human body and antibodies are formed against it. These antibodies bind themselves to their receptors on mast cells and with a subsequent exposure to the same allergen/antigen, antigen-antibody reaction occurs causing the release of histamine. Histamine causes bronchoconstriction leading to the signs and symptoms of asthma which are severe dyspnea and wheezing (Goljan, 2011). Immediate bronchodilation is required to relieve the signs of asthma. The major affects of asthma on respiratory system include deterioration and permanent decrease of the diameter of respiratory pathways. Patient non-compliance due to inability to do anything and permanent shortness of breath. The treatment of asthma include inhalable bronchodilators that are beta-2 agonists e.g. salbutamol. Also, corticosteroids are given in oral, inhalable or injectable forms for their anti-inflammatory action. The antibody involved mainly in inducing an asthmatic attack is IgG and anti-IgG antibody is also useful in the treatment of asthma. (Evolving Asthma Concepts, 2006) Other defects of the respiratory system include atelectasis, pneumoconiosis and bronhiectasis etc. Bronchiectasis is specifically the disease of the bronchi and bronchioles. It is caused when these respiratory passageways are widened more than their normal size due to excessive mucus production which leads to the blocking of these pathways and respiratory obstruction. This is caused mainly by a genetic defect in the mucin gene which causes the over-production of mucous by the glands which eventually leads to its accumulation and obstruction of the bronchi. Another mechanism which causes bronchiectasis is ciliary dyskinesia. Ciliary dyskinesia leads to inability of the cilia to actively move mucus up the respiratory pathway leadig to its accumulation as happens in ciliary disease (Metersky, 2012). The third and final proposed pathogenic theory behind bronchiectasis states that it is caused by aspergillosis and it is known as ABPA (Acut bronchooulmonary aspergillosis). The main affects of bronchiectasis is the widening of respiratory passage. Also, since mucus serves to trap forign particles and bacteria and its upward movement removes these harmful substances, the accumulation of mucus in the respiratory tract leads to accumulation of all these harmful substances as well and makes the respiratory tract more prone to infection and diseases such as pneumonia. There is no permanent treatment of broncihectasis but physiotherapy and anti-mucin agents have been used for the removal of accumulated mucus in the tract for temporary relief from dyspnea. (Metersky, 2012) Pneumoconiosis is another disease caused by the entrance of foreign substances in the respiratory tract. Depending on the type of foreign substance pneumoconiosis is of different types i.e. coal worker pneumoconiosis which is caused by the entrance of carbon in the respiratory tract. These carbon particles when enter the lungs form coal macules and coal granules and leads to destruction of the alveoli. Silicosis is another type of pneumoconiosis which is caused by silicon particles. The two types of silicon i.e. amorphous and serpentine form are responsible for this disease. Of these two types, serpentine form is more responsible and causes the disease more often than the amorphous form. The basic pathology behind the disease is the destruction of alveoli and decrease of surface area for the exchange of gasses. The lungs on cross section give a specific honeycomb appearance and pneumoconiosis and treatment is by the removal of the affected person from exposure to substance. (Cullinan, 2013) Asbestosis is another type of pneumoconiosis which mainly occurs in ship workers. Among other types of pneumoconiosis: siderosis, byssinosis and beryllisosis. These common in pathology and their affects on lung are caused by the inhalation of different substance such as cotton. Beryllium and iron dust etc. Shortness of breath, heavy dark lungs and dyspnea are main findings in these them and removal of the person from the exposed area is the best way of treatment before any irreversible damage has been done. (Cullinan, 2013) References Cullinan, P., & Reid, P. (June 01, 2013). Pneumoconiosis. Primary Care Respiratory Journal, 22, 2, 249-252. Davies, A., & Moores, C. (2003). The respiratory system. Edinburgh: Churchill Livingstone. Evolving asthma concepts. (January 01, 2006). Goljan, E. F. (2011). Pathology. Philadelphia, PA: Mosby/Elsevier. Metersky, M. L., & ODonnell, A. E. (2012). Bronchiectasis. Philadelphia, Pa: Saunders. Read More