Hey, I know this was brought over 3 months ago, however, I would like to share what I know.
RE: voltaes inside our body, it occurs through chemical processes within our cells. It is the foundation of our nervious system, and the pulses that keeps our heart beating are elctrical impulses. That defibliator is not just to shock us back to life. It is to get the heart muscle to respond to those electrical pulses.
That may not be what you are asking about.
Regarding, measuring electricity on the body, skin, tongue..Yes, there is a voltage, and a current. Despite our skins megohm resistance when it is dry, there is still a small voltage and current to the skin.
Measuring skin, and then grounding yourself. And results vary:
The factors
-internal voltage being produced , tiny
-ongoing current from air and environment when body is connected to earth. Not, electrical earth, the planet earth!
-Electrical signals, radio, TV, Wifi, even cordless phones and maybe Bluetooth, if you have your nose in btwn the signal. (that might be a fun test. Try to find any voltage from a Bluetooth signal!)
- also, reflections or radio waves around you from various objects.
Now to dispel what I have repeating seen on YouTube about EMF increasing when our body is grounded. There are people selling "EMF grounding matts" out there for your health. When we as humans are grounded to earch ground, we become conduit, or antenna for any electircal or elctr-magnetic energy. This is normal (the electro-magnetic)
The air may be positively or negatively charged. We can make great earth round. Static build up..
most, if not all, voltage measured on our bodies comes from the air or nearby EMF fields. radio signals, Air +/- ion balance, electrical field, and so forth.
I have had great fun exploring what voltage I find on my body in diferent situations. I use hand to hand, or throat to hand, or heart to hand. What i have learned is that the voltage is stronger when measured near an artery!
I have also learned that in my small office with metal furniture and storage all around, i have created an incomplete Faraday cage. Either I should seal and work within, or ground it, because th voltage substantially increases. One Day.
One final note. Perhaps you have heard about all the concern of EMF effects on our body. This has been an argument for around 30 years. Some states have set standards limiting the amount of EMF in homes,businesses, and school playgrounds. There is danger at very high levels. however, there is some interesting study out there, that say moderate EMF in your home and office may actually may affect your health. however, it is not from what has been argued about for 30 years, rather the physical fatigue experienced by some people being around digital signals. they think it might come from the great increase in digital signal generation affects us because that on/off, non-sinusoidal energy is like a person tapping you continually. With some much of this energy, these "micro" taps accumulate into "bigger" taps, and in so much ot the world, it is unavoidable and 24/7
Personally, I find this this theory fascinating. I wonder what may change in the future. And, what hard science may reveal to us about these matters.
Cheers!