  In an approach inspired by Polyakov loop extended NJL models, we present a
nonlinear hadronic SU(3) sigma-omega mean field model augmented by quark
degrees of freedom. By introducing the effective Polyakov loop related scalar
field \Phi and an associated effective potential, the model includes all known
hadronic degrees of freedom at low temperatures and densities as well as a
quark phase at high temperatures and densities. Hadrons in the model exhibit a
finite volume in order to suppress baryons at high T and \mu. This ensures that
the right asymptotic degrees of freedom are attained for the description of
strongly interacting matter and allows to study the QCD phase diagram in a wide
range of temperatures and chemical potentials. Therefore, with this model it is
possible to study the phase transition of chiral restoration and deconfinement.
In this paper, the impact of quarks on the resulting phase diagram is shown.
The results from the chiral model are compared to recent data from lattice QCD.
