Explaining A Function Of Quartz Circuits?

[Ishima]

It's always bothered me about quartz watches how many will vary the current they take from the cell to compensate for increased physical resistance, either from debris, poor lubrication or the need to change calender positions etc. 

My question is, how exactly does the integrated circuit get this information, I'm presuming it's measured somehow from the stepping motor. but I'm struggling to understand how the circuitry could be aware of it, or of any of the physical, moving, mechanical pieces of the quartz watch. 

Early on in my career I always imagined the quartz circuit and the moving parts to be two totally independent assemblies, The circuit blindly fulfills it's electrical function, and then the resulting, well timed magnetic field changes from the coil cause a change in the stepping motor and then it goes from there... Of course these days I know that's not true, at least not strictly, I've just never come to an understanding of how it's not true. 

I hope I've explained my confusion properly, is anyone capable of explaining this? It's not something I've come across in my textbooks/online. 

Edited July 3, 2015 by Ishima