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Unformatted text preview: onditions. These effects can result in increased medication use, increased doctor or emergency room visits, more hospital admissions and even premature death. Human Respiratory System Human Cardiovascular System Heart and Lung Diseases Pyramid of Health Effects Populations at Risk Leading Causes of Hospitalization Leading Causes of Death Estimating Health Benefits Human Respiratory System
The health of our lungs and entire respiratory system is affected by the quality of the air we breathe. In addition to oxygen, this air contains other substances such as pollutants, which can be harmful. Exposure to chemicals by inhalation can negatively affect our lungs and other organs in the body. The respiratory system is particularly sensitive to air pollutants because much of it is made up of exposed membrane. Lungs are anatomically structured to bring large quantities of air (on average, 400 million litres in a lifetime) into intimate contact with the blood system, to facilitate the delivery of oxygen. Lung tissue cells can be injured directly by air pollutants such as ozone, metals and free radicals. Ozone can damage the alveoli -- the individual air sacs in the lung where oxygen and carbon dioxide are exchanged. More specifically, airway tissues which are rich in bioactivation enzymes can transform organic pollutants into reactive metabolites and cause secondary lung injury. Lung tissue has an abundant blood supply that can carry toxic substances and their metabolites to distant organs. In response to toxic insult, lung cells also release a variety of potent chemical mediators that may critically affect the function of other organs such as those of the cardiovascular system. This response may also cause lung inflammation and impair lung function. Structure and Function The human respiratory system is dominated by our lungs, which bring fresh oxygen (O2) into our bodies while expelling carbon dioxide (CO2). The oxygen travels from the lungs through the bloodstream to the cells in all parts of the body. The cells use the oxygen as fuel and give off carbon dioxide as a waste gas. The waste gas is carried by the bloodstream back to the lungs to be exhaled. The lungs accomplish this vital process - called gas exchange - using an automatic and quickly adjusting control system. This gas exchange process occurs in conjunction with the central nervous system (CNS), the circulatory system, and the musculature of the diaphragm and th...
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This note was uploaded on 05/06/2008 for the course HIST 101 taught by Professor Joe during the Spring '08 term at Waubonsee.
- Spring '08