Power Tools for Technical Communication:
Process Discussion Formatting

In this lab, you add headings, lists, and illustrations to the unformatted text of a process discussion and create a web page. To be ready for this project, you need to have have studied Chapter 17 in Power Tools for Technical Communication and have done at least one other web-page formatting project:
  1. Using a simple text editor or web-page editor of your choice, create a simple web page like the one shown in Chapter 17 entitled My First Web Page. Between the <TITLE> and </TITLE> tags and between the <H1> and </H1> tags, substitute Web Page Process Discussion.
  2. Copy the following unformatted the text, and paste it into the web page you just started.
  3. Study the unformatted text carefully, rearrange the paragraphs as necessary, add headings, and reformat text as numbered or bulleted lists as necessary.
  4. Copy the graphics (located just below the unformated text) for the text you are working on. Insert those graphics where they belong in the text, and add labels and figure titles, and cross-references.
  5. Put your name, Process Discussion Format, and the date on this document, and print it out for your instructor.

Respiration is the process by which organisms generate the energy they need in order to function properly and can be summarized by the following equation: nutrients + oxygen => carbon dioxide + water + energy. As humans, the nutrients come from the food we eat and are typically sugars, while oxygen is taken from the air we breathe. This process is the same for all mammals. Other types of organisms may use other sources. For example, fish get their oxygen from the water they swim in. Respiration in humans can be broken down into the following steps: oxygen-rich air breathed in; oxygen in air transferred to the bloodstream (in the lungs); oxygen in blood transported to cells; chemical reactions in cells use up oxygen and produce carbon dioxide; carbon dioxide-rich blood transported to the lungs; carbon dioxide in the bloodstream transferred to air (in the lungs); and carbon dioxide-rich air breathed out.

As you inhale, you are taking air into your body. This contains about 21% oxygen, with only about 0.03% carbon dioxide. With each breath, this air is drawn into the lungs. Once the air is in the lungs, oxygen is transferred into the bloodstream by way of the alveoli (tiny thin-walled, air-filled sacs that are surrounded by capillaries). Oxygen molecules pass through the walls of the alveoli and into the red blood cells, where they are held until required. Once in the bloodstream, the oxygen needs to be taken to where it is needed—the cells. For example, muscle cells need oxygen so that they can produce the energy needed to make the muscle contract. Almost all the cells in the body are supplied with oxygen via the blood. The oxygen-rich blood (oxygenated blood) from the lungs flows into the heart, where it is pumped out through the aorta. The blood passes through arteries and then arterioles which get smaller and smaller until it gets into the capillary network. Oxygen can now pass out of the red blood cells and across the extremely thin capillary walls into the surrounding tissues, which contain the cells which need it.

Cells in our bodies need energy to perform certain processes, such as contracting (cells in the muscles) or producing chemicals such as insulin (pancreas) and adrenaline (adrenal glands). They obtain this energy through cellular respiration – the conversion of nutrients and oxygen into carbon dioxide, water and energy: nutrients + oxygen => carbon dioxide + water + energy. The nutrients used are typically sugars stored in the cell, for example, glucose: C6H12O6 (glucose) + 6O2 ? 6CO2 + 6H2O + energy. Therefore, for each oxygen molecule used, a molecule of carbon dioxide is produced as waste. This waste passes out of the cell, through the capillary wall and into a red blood cell. The transfer of gases between cells and the bloodstream is a two-way process. As oxygen is taken out of the red blood cells in the oxygenated blood, it is replaced with carbon dioxide to give deoxygenated blood.

Once the carbon dioxide from cellular respiration passes into the bloodstream, it flows through venules and veins which get progressively larger and eventually lead to the heart, where the deoxygenated blood is pumped back into the lungs. Deoxygenated blood in the lungs flows into the capillaries surrounding the alveoli, where the carbon dioxide passes out of the bloodstream and into the air held in the lungs. At the same time, oxygen passes out of the lungs and into the blood, which becomes oxygenated. As you exhale, air in the lungs is forced out of the body. This air contains about 15% oxygen, with about 4% carbon dioxide* and an appreciable quantity of water vapor. The overall change in composition between air breathed in and out is summarized in the following: for nitrogen, 78% is breathed in, 78% is breathed out; for oxygen 21% is breathed in, 15% is breathed out; for carbon dioxide 0.03% is breathed in, 4% is breathed out; for water vapor <1% is breathed in, 2% is breathed out; for others <1% is breathed in, <1% is breathed out. These figures show that more oxygen is inhaled than exhaled, while more carbon dioxide is exhaled than inhaled. This is a result of respiration; some of the oxygen is used up, reacting to give carbon dioxide. The proportions of oxygen and carbon dioxide in the air we exhale vary. For example, when doing vigorous exercise the cells in our muscles have to work much harder, and hence use more energy. As a result, these cells convert oxygen to carbon dioxide much more quickly than when at rest. Therefore, there is less oxygen and more carbon dioxide found in exhaled breath when exercising than when resting.

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