Tissue bioelectric organization

Bioelectric Organization of Nervous Tissue. The membrane potential of 70 mV is developed across the lipid bilayer of the cell membrane. This layer is approximately 40 8 thick, so that the transmembrane electric gradient is of the order of 105 V/cm. This extraordinary dielectric strength is not easily replicated in artificial materials. It is noteworthy that the resting membrane potential maintains this dielectric bilayer within a factor of two of electrical breakdown (19). Release of neural transmitter substances from synaptic terminals on the nerve cell surface transiently shifts the membrane potential at the site of release by a few millivolts. In terms of an altered transmembrane gradient, this shift is of the order of 1.0 kV/cm. 

Bioelectrical impedance. This technique involves connecting electrodes to the hands and feet and passing a mild electric current through the body. Most organs and tissues conduct the electric current, as they contain water and salts. However, adipose tissue contains only about 14% water, by weight, and does not readily conduct electricity. The results give an indication of total body fat. 

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