Getting Started: The Approach to Respiratory Physiology

The Keys to the Vault: Helping You Master the Material

As teachers, we want our students to be able to think critically; as students, you hope to be able to demonstrate critical thinking. To think critically about physiology and your patients, you must be able to understand concepts, not merely so they can be repeated but also in a way that they can be applied to new situations. To do this, you must achieve a level of understanding that is more than skin deep; you must have an intuitive feel for the concepts and their implications for the body's function. You must be able to manipulate the principles so they can shed insight on puzzles and open doors for the way out of the maze. To help you achieve this goal, we have taken an approach that is more conceptual than quantitative. We emphasize the equations and calculations you will need as a clinician and otherwise use numbers when doing so will enhance understanding rather than distract from it. We have provided a number of learning tools that are intended to help you develop the depth of understanding necessary for you to be able to think critically as a clinical physiologist.

Animated Figures ↑

To give you a chance to work with the concepts developed in the text, you will have opportunities to try a variety of computer-based animations and simulations. These interactive diagrams are designed to allow you to view an animation of a concept, or to manipulate, at your own pace, a number of variables that change over a range of physiologic conditions. You can experiment by changing parameters, predict the consequences of these changes, and then puzzle over which principles accounted for the transition from the first condition to the second. For visual learners (and for those who believe that "a picture is worth a thousand words"), these learning opportunities will enhance the text. In certain cases, we provide simultaneous auditory, textual, and animated material to engage your senses in the learning experience.

In some of the more complex Animated Figures, you should focus on one aspect of the animation at a time and then sit back and see if you can integrate everything that is happening at once. In essence, focus on one part of the puzzle and then another until the entire picture reveals itself to you. For example, take a look at Animated Figure 1-2.

A patient is shown breathing on a water spirometer. As the patient exhales, the expired gas forces the spirometer drum up; during inhalation, the drum descends. The movement of the drum is transformed into movement of a pen, and the system is calibrated so that the vertical motion can be translated into changes in volume. At the start, the figure depicts the patient at a lung volume called functional residual capacity. Note that at this lung volume, inward force exerted by the lungs (the elastic recoil of the lungs) is equal in magnitude but opposite in direction to the outward recoil force exerted by the chest wall. This Animated Figure reappears with a fuller explanation in Chapter 3.

Thought Questions ↑

In the early 20th century, the world-renowned physicist Albert Einstein created gedanken experiments, or thought experiments, to help him analyze the forces of the universe. These were experimental situations that he worked through intellectually rather than physically to find fallacies in his reasoning. In the spirit of Einstein, we have interspersed thought questions throughout the text to assist you in working through concepts and principles of respiratory physiology. We urge you to take the time to ponder the thought questions when they arise because they are strategically placed to reinforce the concepts developed up to that point in the text and Animated Figures. Thus, an inability to answer the thought question should prompt you to revisit the material that precedes it.

Review Questions ↑

At the end of each chapter, the review questions will enable you to do a self-assessment of your learning. The questions are based on mini case scenarios. Answers to the review questions accompany each question but are hidden to start. Try the question before viewing the answer—this effort will strengthen your learning. In addition, a glossary of terms is included at the end of the text to facilitate your learning of the vocabulary of respiratory physiology.