Ventilation of the lungs is controlled by the brain, which processes information sent from stretch receptors in the lungs and sends back information to tell the muscles in the chest and diaphragm when...

Ventilation of the lungs is controlled by the brain, which processes information sent from stretch receptors in the lungs and sends back information to tell the muscles in the chest and diaphragm when to contract and relax so that the lungs are inflated just the right amount. To explore the quantitative nature of this control in detail, Zuperku and Hopp † measured the output of stretch receptor neurons from the lungs during a respiratory cycle. To see how control signals from the brain interacted with this output, they stimulated nerves leading to the lungs at four different frequencies F, 20, 40, 80, and 120 Hz and measured the change in output in the stretch receptor nerves ΔS. As part of the analysis, they wanted to know how the normal stretch receptor nerve discharge S affected the changes ΔS and how this relationship between ΔS and S was affected by the frequency of stimulation F (the data are in Table D-11, Appendix D). A. Find the best-fitting regression plane relating ΔS to S and F. B. Interpret the results.

Table D-11