sustentative functions

from The Collaborative International Dictionary of English v.0.48

Sustentative \Sus"ten*ta*tive\, a.
   Adapted to sustain, strengthen, or corroborate; as,
   sustentative citations or quotations.
   [1913 Webster]

   {Sustentative functions} (Physiol.), those functions of the
      body which affect its material composition and thus
      determine its mass.
      [1913 Webster]