Homeostasis is simply keeping the environment under your best control. Much of that is under the auspices of the central nervous system and peripheral nervous system, but also your autonomic system as well (both sympathetic and parasympathetic components). While the blood system helps with maintaining nutrition levels and waste removal, the lymphatic system (with twice the fluid in it than the cardiovascular system) also helps maintain a recycling of materials needed for detoxification and molecular repair production.