  We explore the phase diagram and the modification of mesonic observables in a
hot and dense medium using the (2+1) Polyakov-Nambu-Jona-Lasinio model. We
present the phase diagram in the ($T,\,\mu_B$)-plane, with its isentropic
trajectories, paying special attention to the chiral critical end point (CEP).
Chiral and deconfinement transitions are examined. The modifications of mesonic
observables in the medium are explored as a tool to analyze the effective
restoration of chiral symmetry for different regions of the phase diagram. It
is shown that the meson masses, namely that of the kaons, change abruptly near
the CEP, which can be relevant for its experimental search.
