Propagation of Action Potential

[jackyM]

Hello all..
I would like to know the propagation procedure of action potential in these 3 situations:

1) propagation within the cell
2) Propagation from cell to cell
3) Propagation from cellular actiosn to ECG

As far as i understood , the propagation within the cell is basically the normal mode of propagation of action potential in neurons with these 5 phases {1)Resting Potential 2)Threshold 3)Rising Phase 4)Falling Phase 5)Recovery}
The currents flowing inwards at a point on the axon during an action potential spread out along the axon, and depolarize the adjacent sections of its membrane. If sufficiently strong, this depolarization provokes a similar action potential at the neighboring membrane patches. Is this propagation within the cell??

How does it propagate from one cell to another? and also to ECG??

Thanks for any help

[JackBean]

from cell to cell is the action potential propagated through synapses you could know that
what is ECG?

[jackyM]

thnx for the reply... i was not sure abt synapses. thats y i asked.
ECG means Electro Cardiogram. I guess the propagation of cellular actionpotenial to ECG is same as Cardiac Action Potential.
http://en.wikipedia.org/wiki/Cardiac_action_potential

[JackBean]

are we talking about neurons in 2), rigth?

[jackyM]

i was actully focussing on the action potential involving in the cardiac area i.e to find the relationship between cellular action potential and the electrical action as seen on the body surface, that is the ECG.

[TATAbox]

The action potential propagates from one myocyte to another through gap junctions. The electric currents produced by the exchange of ions through the cell membrane simply flow from one cell to the next through those junctions.

[JackBean]

OK, well then forget everything about the synapses