Fig. 11

Schematic presentation of the average changes of activity of 3 different types of sympathetic efferents in response to electrostimulation in the defense area (stim Hypothal.). Skin vasoconstrictors (vasoconstrictor skin), displaying spontaneous activity before stimulation are generally activated during stimulation. Muscle vasoconstrictors (vasoconstrictor, muscle), which are also spontaneously active before stimulation, are activated more variably and display, on the average, a temporally modulated response. Muscle vasodilator fibers (vasodilator, muscle) do not show spontaneous activity during pre- and post-stimulation periods. They are strongly activated during defense area electrostimulation (see Fig. 12). Change of blood flow (electromagnetic flow probe) in the lumbar aorta (bloodflow) is mainly attributable to the change in skeletal muscle blood flow which is dominated by the sympathetic vasodilator innervation. From data of Horeyseck et al. [21]