My understanding is that if the elevator is deflected upwards, to trim this the stabiliser will reduce angle of attack (leading edge down), it essentially moves to bring itself into line with the elevator.
The logic: reduced angle of attack means less lift, therefore the nose pitches up.
I haven't got a clue what happens if it sticks in cruise, though i was told once that on the old 737 classics (talking 100/200 series) the pilots could overcome the forces required to pitch the a/c by sticking their feet on the dash and pulling hard!