Student Investigation 2.4

Background
At the beginning of this Case Study, you were introduced to the concept of respiration. There are four measurable respiratory volumes that are important indicators of respiratory fitness: (1) tidal volume (TV), (2) inspiratory reserve volume (IRV), (3) expiratory reserve volume (ERV), and (4) vital capacity (VC). (The term capacity is used to refer to a volume that is obtained by adding together two or more other volumes.) The residual volume (RV) is not an easily measured value, but there is an accepted standard value attached to this volume that can be used when needed for calculations or graphing exercises. From these measurements, one can obtain, through calculation, the total lung capacity (TLC). A table of definitions for these respiratory measurements was presented and explained to you earlier in this Case Study; you will find that table reproduced here for your convenience.

You will be instructed to obtain your personal respiratory measurements in the next Student Investigation. Before we move forward to that step, however, it is important to be able to graphically interpret the respiratory measurement definitions that you have already become familiar with.

Procedure
Each student should carry out this exercise independently. Your teacher will provide a separate handout for you to complete. Examine the respiratory measurement definitions in Table 1 in the Earth Physiology section and use those definitions to fill in the blanks on the graph in Figure 17.

Figure 17. Lung volume measurements. Using the definitions in Table 1, fill in the blanks.