Bulges
  We model the evolution of the galactic bulge and of the bulges of a selected sample of external spiral galaxies, via the multiphase multizone evolution model. We address a few questions concerning the role of the bulges within galactic evolution schemes and the properties of bulge stellar populations. We provide solutions to the problems of chemical abundances and spectral indices, the two main observational constraints to bulge structure. 
M. Molla (1), F. Ferrini (2) and G. Gozzi (2) ((1) Universidad   Autonoma de Madrid (Spain), (2) Universita di Pisa (Italy))