Galactic bulges

We model the evolution of the Galactic bulge and of the bulges of a selecte d sample of external spiral galaxies, via the multiphase multizone evolutio n model, We address a few questions concerning the role of the bulges withi n galactic evolution schemes and the properties of bulge stellar population s. We provide solutions to the problems of chemical abundances and spectral indices, the two main observational constraints to bulge structure.