According to this the Core did proceed down to an antimatter souce. Produced by Paramount from this illistrator.
Not to be pedantic but the sheet itself says 1701-A. He's working on TMP ship. Add in that the only time we saw engineering of the 1701-A it was a scant redress of TNG's Engineering and we can see the engineering core/intermix is the wrong design on the sheet anyway.
Anyway, as to what things are called, there's also Andy Probert's drawing which has some labels with the vertical shaft "impluse" and the horizontal "warp"