Originally Posted by Rothbard
if i understand cell physiology correctly, plasma has a negligible positive charge. nearly all objects a human interacts with on a daily basis are electrically neutral. anything that is even slightly charged gives you a "static shock" as the charge gradient is dissipated.
bulk electroneutrality must be maintained - this means that all regions of the human body are electrically neutral at the cellular level. the electrostatic force is extremely strong - even a slight difference in charge produces a powerful force. if there were a significant charge difference between the intracellular fluid and the plasma, the cell membrane would quickly be ripped apart by ions moving down their charge gradients.
a relatively small charge separation (so small as to be negligible) can support a large concentration gradient
No this is not correct. All cells in the body have a net positive charge outside or net negative inside dept on how you want to look at it. Most cells use the NA/K ATPase antiporter to accomplish this. 3 Na+ out 2 K in. The Na gradient drives everything from nerve action potentials to renal filtrate modulation to cardiac contractility via driving calcium antiporters. This is clear when looking at a neuron membrane potential of ~ -90mV w respect to the inside. If not for electrical gradients EKGs and EEGs would not work. There are several examples of cells taking differential advantage of concentration or electrical gradients to accomplish work. I'm a little low on examples bc this post is being written while on a bathroom break (sdn>sports page)
As for blood, the coagulative components tend to have a negative charge but the serum over all is slightly basic and the auto ionizing property of water will neutralize charge. The reason for the negative charge is anti coagulation when interacting (or not) with negative charges on healthy endothelium
A net neutrality within compartments should not be confused with absence of charge separation.