The Thermally Pulsing Asymptotic Giant Branch (TP-AGB) phase is
characterised by an extraordinary richness of physical processes which
include a unique nucleosynthesis and mixing processes, radial pulsations
and shocks, abundant formation of molecules, dust condensation and growth,
and stellar winds.
We will travel through the physical structure of TP-AGB stars showing how
the events that occur in the deep interiors are expected to affect
dramatically the surface properties and the ejecta up to large distances
(several stellar radii).
In this framework I will report on ongoing efforts aimed at linking the
evolution and nucleosynthesis of TP-AGB stars with the chemical, dynamic
and photometric properties of their circumstellar envelopes.