It will be documented that the oxygen molecule, which basically glides through the air, happens to breathed in via the nose and mouth in the course of inhalation. It then moves from the nose and mouth into the pharynx, precisely, to the nasopharynx and oropharynx. Studies hae extended to reveal that the epiglottis in return closes so as to inhibit foreign substances from flowing into the windpipe (trachea). As it moves from pharynx, oxygen molecule passes through the voice box (larynx) via the trachea. It will be realized that the trachea actually separates into bronchi, which are mainstream branches that enter into each lung (Taylor, n.d.). When the oxygen molecule is in each bronchus, it travels via the smaller branches known as bronchioles, and further proceeds to alveoli. It is generally agreed that this oxygen molecule clearly filters through or passes across the alveoli. It will further be recognized that within the alveoli, there are small pulmonary capillaries which pass by. As soon as the oxygen moves through the alveoli, then the oxygen molecule jump onto or transfers to hemoglobin molecule within red blood cells (erythrocytes) to the blood via thin walls within the alveoli, and, further, through the alveolar and pulmonary capillaries, hence forming oxygen-rich blood. Simultaneously, carbon dioxide, which is body cells’ waste product, jumps off or transfers from hemoglobin molecule, and eventually expelled in the course of exhalation.
Basically, the oxygen molecule within the blood, specifically the oxygen-rich blood, moves from the lungs towards the heart via the pulmonary veins and veinioles, and then to the left atrium, so as to provide oxygen in the heart (Whitfield, 2006). The oxygen molecule further moves from left atrium via the bicuspid valve towards the left ventricle. From this chamber, the oxygen molecule is then driven out of the heart via aortic semi-lunar valve, towards the aorta, which is the largest artery, and, further, travels to the body so as to provide the entire body with sufficient oxygen. Research discloses that the oxygen molecule moves all over the body via the arteries and arterioles up to the capillary beds within the tissues. As the blood is within capillary beds, oxygen molecule jumps off or transfers to the hemoglobin molecule found within red blood cells via the thin walls of the capillaries, and, at that time supplies tissues as well as cells with oxygen. The carbon dioxide, which is basically a waste product from the cells, then moves to the opposite direction via capillary walls so as to be absorbed by the blood. Since oxygen molecules are in the body, the un-oxygenated returns to the heart.
It is believed that emphysema is a long-term and progressive lung disorder, which primarily leads to shortness of breath as a result of over-inflation of alveoli. It will be documented that emphysema generally affects lungs through destroying the alveoli. As one inhales air, then, the alveoli stretch so as to draw some oxygen in, where it is, further, conveyed into the blood. On the other hand, when one breathes out, the alveoli shrink, thus forcing the carbon dioxide to move out. As soon as emphysema develops, then, the elasticity of the alveoli fades leading to destruction of the lung tissue. Consequently, the air turns out to be trapped within the lungs, and thereby over-extending them, making the alveoli to burst. The trapped air implies that less oxygen ends up reaching the blood (Barnes, 2009). Moreover, the over inflation further subjects constant pressure to the lungs, compelling them to stretch further than their ordinary limits, giving most of the patients suffering from emphysema to have a barrel-chested appearance.
Barnes, P. J. (2009). Asthma and COPD basic mechanisms and clinical management (2nd Ed.). Amsterdam: Elsevier/Academic Press.
Taylor, T. (n.d.). Respiratory System. Retrieved from http://www.innerbody.com/anatomy/respiratory.
Whitfield, J. (2006). In the beat of a heart: life, energy, and the unity of nature. Washington, D.C.: Joseph Henry Press.