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Unformatted text preview: e chest. The human respiratory system can be divided into the upper respiratory tract and the lower respiratory tract. The upper respiratory tract includes the following rigid structures: Nasal cavities: Filter the air we breathe and provide a sense of smell. Pharynx: Acts in the respiratory and the digestive system. Larynx: Link between the pharynx and the trachea. Generates the voice with the presence of vocal folds. Trachea: The trachea is the bond with the lower respiratory tract. This is a flexible structure allowing the air to go down to the lungs. In addition to gas exchange, the lungs and the other parts of the respiratory system have important jobs to do related to breathing. These include: Bringing all air to the proper body temperature. Moisturizing the inhaled air for necessary humidity. Protecting the body from harmful substances by coughing, sneezing, filtering or swallowing them, or by alerting the body through the sense of smell. Defending the lungs with cilia (tiny hair-like structure), mucus and macrophages, which act to remove harmful substances deposited in the respiratory system. Diagram of Human Respiratory System The respiratory system is sensitive to air pollution. The cardiovascular system can be affected as well. Human Cardiovascular System
The cardiovascular system has two major components: the heart and a network of blood vessels. The cardiovascular system supplies the tissues and cells of the body with nutrients, respiratory gases, hormones, and metabolites and removes the waste products of cellular metabolism as well as foreign matter. It is also responsible for maintaining the optimal internal homeostasis of the body and the critical regulation of body temperature and pH. The inhalation of air pollutants eventually leads to their absorption into the bloodstream and transport to the heart. A wide spectrum of chemical and biological substances may interact directly with the cardiovascular system to cause structural changes, such as degenerative necrosis and inflammatory reactions. Some pollutants may also directly cause functional alterations that affect the rhythmicity and contractility of the heart. If severe enough, functional changes may lead to lethal arrhythmias without major evidence of structural damage to the myocardium. There also may be indirect actions secondary to changes in other organ systems, especially the central and autonomic nervous systems and selective actions of the endocrine sy...
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- Spring '08