our nervous system is organized into two broad anatomical divisions: the central nervous system (consisting of the brain and spinal cord) and the peripheral nervous system (PNS). Your PNS is further organized into two functional divisions. If you tap your knee, the signal to act is carried via your ____ to the muscles in your knee. In contrast, the signals that pass via the ____ are involuntary and act primarily to regulate your body's internal environment. This involuntary nerve system is further organized into three divisions. If you need a sudden burst of energy, your ____ is activated to help you act quickly. In contrast, if you are relaxing and conserving energy, then it is your ____ that is primarily in action. The third division is your _____ which helps control the components of the digestive system.