To an insurance company, an insurable interest is the basic reason for issuing a legal insurance cover, to an insured (or beneficiary) it gives the legal right to enforce an insurance claim.
The change in membrane potential occurring in nerve, muscle, or other excitable tissue when excitation occurs. action potential. A momentary change in electrical potential on the surface of a neuron or muscle cell. Nerve impulses are action potentials.
Action potentials are generated by special types of voltage-gated ion channels embedded in a cell's plasma membrane. These channels are shut when the membrane potential is near the resting potential of the cell, but they rapidly begin to open if the membrane potential increases to a precisely defined threshold value.