The autonomic nervous system has two divisions: The sympathetic division acts to energize the body, preparing it for action. The parasympathetic division acts to calm the body, allowing it to rest. Our everyday activities are controlled by the interaction between the sympathetic and parasympathetic nervous systems.
Update: N2Aos is now available for Kindle Fire HD and Kindle Fire HD 8.9. And you get the full Android experience here, including access to the Google Play store and all the other features offered by Android 4.2 (excepting what's not available via hardware, of course).
The Amazon Fire HD 10 is not a good tablet and does not live up to the standard set by its predecessors and Amazonâs other hardware. The new Fire OS 5 has some good ideas and is a step up from the previous versions of the operating system.