I can't think of what to call these except 'fills', but here are a few options that come to mind.

1) Chord notes

2) Scale notes

3) Chromatic notes (well that means pretty much everything!)

Another thing I remember from bass note leading is a full tone above the note you are approaching followed by a 1/2 tone below the note, and then to the note....

Cheers,

SarinaJ :o