In Chapter 1 I described the anatomical and physiological characteristics of the peripheral autonomic nervous system on the macroscopic level. The overall conclusion from this conservative approach is that the peripheral autonomic neurons are integrated in the neural regulation of many target cells of the body (see Table 1.2). In other words, peripheral autonomic pathways that transmit signals from the spinal cord and brain stem to the peripheral effector cells must have some functional specificity with respect to these effector cells, in the sympathetic and the parasympathetic nervous system. Otherwise it would be impossible to understand how the precise autonomic regulation that is the basis for the continuous adaptation of the body during various demands occurs. Implicit in this idea is that these peripheral autonomic pathways are connected to distinct neuronal circuits in the spinal cord, brain stem, hypothalamus and telencephalon.

In this and the next chapter I will give arguments, and describe in some detail, that principally each type of target cell that is innervated by autonomic neurons is influenced by one or two autonomic pathways and that these pathways transmit distinct messages to the periphery and are connected to distinct central circuits. This chapter describes the final autonomic pathway and its analysis. It concentrates particularly on the neurophysiological analysis. Morphological analysis of autonomic circuits will be described in Chapter 8 and elsewhere in the book.