  Within conventional constituent-quark models hadrons come out as stable bound
states of the valence (anti)quarks. Thereby the resonance character of hadronic
excitations is completely ignored. A more realistic description of hadron
spectra can be achieved by including explicit mesonic degrees of freedom, which
couple directly to the constituent quarks. We will present a coupled-channel
formalism that describes such hybrid systems in a relativistically invariant
way and allows for the decay of excited hadrons. The formalism is based on the
point-form of relativistic quantum mechanics. If the confining forces between
the (anti)quarks are described by instantaneous interactions it can be formally
shown that the mass-eigenvalue problem for a system that consists of dynamical
(anti)quarks and mesons reduces to a hadronic eigenvalue problem in which the
eigenstates of the pure confinement problem (bare hadrons) are coupled via
meson loops. The only point where the quark substructure enters are form
factors at the meson-(bare) hadron vertices. The physical picture that emerges
resembles the kind of hadronic resonance model that has been developed by Sato
and Lee and is now heavily used at the Excited Baryon Analysis Center (EBAC) to
fix $N^\ast$ properties. Our approach, however, is in a certain sense inverse
to the one of Sato and Lee. Whereas they want to undress physical resonances to
end up with bare quantities, we rather want to dress the bound-states resulting
from a pure constituent quark model to end up with quantities that can be
directly compared with experiment. The way how our approach works will be
exemplified by means of a simple quark-antiquark-meson system.
