  Starting from the approximate symmetries of QCD, namely chiral symmetry for
light quarks and spin and flavor symmetry for heavy quarks, we investigate the
low-energy properties of heavy hadrons. For this purpose we construct a
consistent picture of quark-antiquark and quark-diquark interactions as a
low-energy approximation to the flavor dynamics in heavy mesons and heavy
baryons, respectively. Using standard functional integration tools, we derive
an effective Lagrangian in terms of heavy hadron fields and discuss several
properties, like the mass spectrum, coupling and decay constants, Isgur-Wise
form factors.
