Advances in Physiology Education, Vol 267, Issue 6 65-S76, Copyright © 1994 by American Physiological Society
Hydraulic analogs as teaching tools for bioelectric potentials
J. Procopio
Departamento de Fisiologia e Biofisica, Universidade de Sao Paulo, Brazil.
Hydraulic analogs of bioelectrical potentials are proposed as teaching
tools in helping students with no formal background in physics and
mathematics. Membrane capacitance is simulated by a water reservoir, V,
whose variable level is the membrane potential. Resting membrane potential
is simulated by a large capacitance reservoir of fixed level, connected to
reservoir V through a tube having the role of the electrical conductance of
the membrane. Injection of electrical current into the cell is simulated by
injection of water into the membrane capacitance reservoir. Reversal
potentials of the end-plate potential are simulated by another water
reservoir, with fixed level (analogous to the reversal potential of the
end-plate potential) connected to the membrane capacitance reservoir
through a tube corresponding to the acetylcholine-activated ion channels.
Different phases of the synaptic potential are then described using the
hydraulic analogs. Hydraulic analogs have proved, in our experience, to be
an efficient tool in complementing the already established electrical
equivalents.
