Why do we feel electrical shocks? So electrical energy from source to device flows in the direction of the Poynting vector. My question is what do we feel exactly when we get an electrical shock? Before I learned about Poynting and how energy flows, I just thought somehow we felt the electrons through our body and that gave a shock or something. But how does it work actually? You become part of the electrical circuit, energy flows through you, why does that hurt, or even deadly?
Sorry if my question is stated vaguely, I don't really know how to explain it.
 A: A biologist could answer this question in more detail.
Static discharges sting because they are hot. In extreme cases (for instance: being struck by lightning, or wearing metal jewelry while being electrocuted) they can cause burns.
The jolting sensation associated with being zapped (or of being harmfully electrocuted), whether by static discharge or continuous current, comes because your muscles are electrically activated, chemically powered machines. Any large current across a muscle causes chemical processes which make the muscle contract. The feeling of impact in your finger when you zap yourself on a door knob is the sensation of the small muscles at the very tip of your finger flexing.
If the current crosses the heart, the sudden contraction can cause potentially fatal heart arrhythmias. (A defibrillator machine or a pacemaker applies the same principle in reverse to fix some arrhythmias: a sensor times the delivery of an electric current that overrides the unhealthy rhythm with an induced contraction, and can sometimes restore a healthy rhythm.) Other muscle activations can also cause injury to the musculoskeletal system. Normally your central nervous system turns off the signal telling your muscles to contract before they can cause damage to themselves or connected tissues, but an externally applied current overrides that off switch.
The brain is also a chemically powered machine directed by electrical signals, but it functions with continuous patterns of electrical signaling. Subjecting the brain to an externally applied current may cause bizarre sensations not usually associated with injury, or no sensations at all. In either case, it can cause injury because the current may cause permanent rearrangement of the delicate electrical and chemical patterns that represent faculties of function, memory, and sensation.
A: There exists an E field outside of the wire. Touching that will create a potential difference across your finger. Creating a current in your body, much like a wire. Why this "hurts" I would ask a biologist,  but the "spasm" is because there is now an electric field on your muscles, which causes motion, instead of your brain sending the electrical impulse.
