Pulmonary Physiology

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Pulmonary Physiology and Disorders
One of the main purposes of respiration is gas exchange. The physiological definition of respiration differs from the biochemistry definition of respiration. Physiology defines respiration as movement of air, more specifically oxygen, from the environment to the cells in the body. Biochemistry defines respiration as the metabolic process by which cells utilize glucose and oxygen to produce Adenosine Triphosphate (ATP).
Inspiration, which is an active part of respiration, is initiated by the respiratory control center in medulla oblongata. Nerve impulses from medulla oblongata causes diaphragm and the external intercostal muscles to contract, which leads to the expansion of the thoracic cavity. According
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One of the most common condition is pulmonary edema. Pulmonary edema is caused by leakage of fluid from pulmonary capillaries out into the interstitial space and alveoli. The most common cause of pulmonary edema is either a cardiac or vascular problem. Cardiac problems include mitral valve stenosis or left sided heart failure, both of which increase the pulmonary venous pressure and consequently pulmonary capillary pressure. Vascular problem could arise from an insult to the blood capillary membranes or lung parenchyma caused by infections or inhalation of noxious gases. The main symptom of pulmonary edema is breathing and shortness of breath but it can also present has blood in sputum or excessive sweating. And other signs include and respiratory crackles on auscultation, anxiety, orthopnea, pallor, and also presence of a third heart sound (Ware and Matthay 2005). Radiological studies are usually the best tool to diagnose edema. Chest X-ray usually presents fluid lining the alveolar walls, Kerley B lines, superior lobe diversion (due to increased pleural pressure in the inferior lobes), increased vascular shadowing displayed in batwing pari-hilum pattern, and occasionally pleural effusion. On the other hand, patchy alveolar infiltrates are usually associated with non-cardiogenic edema (Ware and Matthay 2005). Many patients with acute cardiogenic pulmonary edema are hypertensive and have high LAPs but normal cardiac …show more content…
COPD is an obstructive disease that results from inadequate airflow to the lungs over a long period of time. Primary symptoms of COPD include shortness of breath and cough with sputum, which is exacerbated by physical assertion (Vestbo 2014). COPD symptoms are caused by underlying physiological changes in the respiratory system which include loss of alveolar elasticity, respiratory epithelium inflammation and fibrosis, increased mucus production, and at times depletion of the alveolar epithelium. COPD symptoms worsen over time and could get severe enough to even impair common daily tasks such as walking or climbing up the stairs. Most common cause of COPD is cigarette smoking but other factors such as genetics and air pollution also play a minor role (Decramer, Janssens et al. 2012). Usually COPD is diagnosed through pulmonary function tests using spirometry. Two values that are used most often for diagnosing COPD are forced expiratory volume for 1 second (FEV1) and forced vital capacity (FVC). Normally the FEV1/FVC of less then 70% indicates an obstructive disease. That is combined with other symptoms to diagnose COPD (Chou, Qaseem et al. 2011). In case of severe COPD, radiological studies are utilized. To investigate the indication for endoscopic or operative treatment of severe pulmonary emphysema, and to plan these, thin-slice, non-contrast MDCT is recommended (Wielputz, Heussel et al. 2014). Usually the

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