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.
Abundant evidence links sympathetic nervous system activation to outcomes of patients with heart failure (HF). 1 In contrast, parasympathetic activation has complex cardiovascular effects that are only beginning to be recognized.uscarinic receptors are abundant on sinoatrial and atrioventricular nodal cells. The known effects of the parasympathetic nervous system on cardiac function, heart rate, and atrioventricular nodal conduction appear modulated generally via M 2 receptors.