The induced currents

In the conductor, which contains free charge carriers and it is located in non-stacionary magnetic field, an induced electric field is created and an electromotive voltage is induced(Faraday's law).

A current that flows trough a conductor is called the induced current. Induced electric field creates vortices unlike an electrostatic field. It means that its lines of force make closed curves. Lenz´s law: Induced current works against change, which caused him. It always has that direction so that the change would be minimal in induction flux accross the surface.

A self induction
The magnetic field and magnetic induction flux is changed when a time-varying current passes through. There is an induced electromagnetic voltage in it. A change in magnetic induction flux is directly proportional to the change in current magnitude.

A mutual induction
If a conductor is near to another conductor through which flows a time-varying current, it will be inducted an electromagnetic field in it and it will flow an induced current.

Effects
An electromagnetic voltage is induced in the tissue due to electromagnetic field. This causes the formation of time-varying electric field and induced currents. If a certain treshold value of voltage is exceed, electromagnetic field will affect a voltage accros the cell wall. The activity of cell receptors, ion channels and total cell activity will also effected and changed by chages of electromagnetic field. Changes in the structere of proteins(enzymes, hormones...)causes a change in their function. They are responsible for induction time-varying electric charges on the surface and inside the body, cell stimulation of neurons and muscle cells.

Reference
NAVRÁTIL, Leoš a Jozef ROSINA. Medicínská biofyzika. 1. vydání. Praha : Grada Publishing, 2005. 524 s. ISBN 80-247-1152-4.