The momenta of individual objects changes. The total momentum remains constant. I have to disagree. If you have two cars that collide head on, the momentum of both vehicles stops. The ENERGY created by the impact causes usually, some reverse momentum but the momentum is lost.
As the SNS continues to trigger physical reactions, it causes a wear-and-tear on the body. It's not so much what chronic stress does to the nervous system, but what continuous activation of the nervous system does to other bodily systems that become problematic.
1). sympathetic system enhances activity 2). The parasympathetic system inhibits activity Thus extrinsic control is the result of a balance between both the parasympathetic and the sympathetic nervous system. A). autonomic nervous system. 1). sympathetic system enhances activity. 2).