In an example in this chapter, we presented data relating to the effect of carotid sinus baroreceptors on nerve discharge. These data related very specifically to the function of a single baroreceptor in terms of the signal it sends to the brain. There are many such baroreceptors feeding information to the brain, which uses the information to control heart rate and vascular resistance to keep blood pressure at the desired normal level. Such integrated responses can be studied using methods similar to those used in the earlier example. Wilkinson and colleagues†

studied the effect of changing blood pressure P using vasodilating and vasoconstricting drugs on the interval between heart beats I in dogs anesthetized with different levels of halothane. A. What is the relationship between I and P with .5 percent halothane anesthesia (the data are in Table D-45, Appendix D)? B. What is the relationship between I and F with 2 percent halothane anesthesia (the data are in Table D-46, Appendix D)? C. Does the baroreceptor sensitivity or set point change with the level of anesthesia?