Measured in volts. In the therapeutic use of electricity, current flow in tissue is discussed as ion flow. Resistance increases as temperature increases. Conductance is mathematically equivalent to the reciprocal of resistance of the conductor. Currents produced in biological tissues are influenced not only by tissue resistance but also by the tissue capacitance.
Impedance is expressed in ohms.
In biological systems, impedance describes the ratio of voltage to current more accurately than does resistance because impedance is a frequency-dependent measure that includes the effects of capacitance, inductance and resistance.