We have left and right sympathetic nervous system even autonomous nervous system. They are supplied by two subtle channels on the left and right side. Then we have parasympathetic nervous system in the center. Supposing you are afraid and you run fast in emergency, so your heart starts pumping more blood and you get higher rate of your pulses. As you know that this is done with sympathetic nervous system. But what brings it down is the parasympathetic, cools it down, is the parasympathetic. This parasympathetic nervous system is also supported by another channel.
Now the fourth energy that we have is a energy by which whatever we achieve in our evolution is recorded, that is our central nervous system. This central nervous system has recorded whatever we have achieved up to this human awareness.