  We present here results of stellar evolution calculations that include the
latest advances in radiative opacities and neutrino cooling, and discuss on the
basis of these models how the internal stellar structure responds to mass-loss
from the stellar surface. This problem has particular importance for the
development of semi-analytical algorithms for effi cient calculation of
synthetic stellar populations with realistic (and hence complex) mass-loss
scenarios. We therefore compare our numerical results with test calculations
based on a semi-analytical stellar evolution method developed by us. Although
small, but important, differences between results from the two methods are
revealed, the evolutionary tracks in the HR-diagram predicted by the two
approaches are almost identical.
