Source : Webster's Revised Unabridged Dictionary (1913)

Internally \In*ter"nal*ly\, adv.
   1. Inwardly; within the enveloping surface, or the boundary
      of a thing; within the body; beneath the surface.

   2. Hence: Mentally; spiritually. --Jer. Taylor.

Source : WordNet®

internally
     adv : on or from the inside; "an internally controlled
           environment" [ant: {externally}]