Context : Apart from its contribution to cosmology , the WMAP data brings new information on the Galactic interstellar medium . In particular the polarization data provide constraints on the Galactic magnetic field and the synchrotron emission , while the intensity data can be used to study the anomalous microwave emission . Aims : The main goals of this study is to use the information from both WMAP intensity and polarization data to do a separation of the Galactic components , with a focus on the synchrotron and anomalous emissions . Methods : Our analysis is made at 23 GHz where the signal-to-noise ratio is the highest and the estimate of the CMB map is less critical . Our estimate of the synchrotron intensity is based on an extrapolation of the Haslam 408 MHz data with a spatially varying spectral index constrained by the WMAP 23 GHz polarization data and a bi-symmetrical spiral model of the galactic magnetic field with a turbulent part following a -5/3 power law spectrum . Results : The 23 GHz polarization data are found to be compatible with a magnetic field with a pitch angle p = -8.5 ^ { \circ } and an amplitude of the turbulent part of the magnetic field 0.57 times the local value of the field , in agreement with what is found using rotation measures of pulsars and polarized extinction by dust . The synchrotron spectral index between 408 MHz and 23 GHz obtained from polarization data and our model of the magnetic field has a mean value of \beta _ { s } = -3.00 with a limited spatial variation with a standard deviation of 0.06 . When thermal dust , free-free and synchrotron are removed from the WMAP intensity data , the residual anomalous emission is highly correlated with thermal dust emission with a spectrum in agreement with spinning dust models . Conclusions : Considering a classical model of the large scale Galactic magnetic field , we show that the polarization data of WMAP are in favor of a soft synchrotron intensity highly correlated with the 408 MHz data . Furthermore the combination of the WMAP polarization and intensity data brings strong evidence for the presence of unpolarized spinning dust emission in the 20-60 GHz range . In preparation for the Planck mission this joint analysis of polarization and intensity data opens new perspective on the study of the Galactic interstellar medium and on the component separation exercise .