Jet propagation and deceleration
  Extragalactic jets in active galactic nuclei (AGN) are divided into two
morphological types, namely Fanaroff-Riley I (FRI) and Fanaroff-Riley II
(FRII). The former show decollimated structure at the kiloparsec scales and are
thought to be decelerated by entrainment within the first kiloparsecs of
evolution inside the host galaxy. The entrainment and deceleration can be, at
least partly, due to the interaction of jets with stellar winds and gas clouds
that enter in the jet as they orbit around the galactic centre. In this
contribution, I review recent simulations to study the dynamic effect of
entrainment from stellar winds in jets and the direct interaction of jets with
gas clouds and stellar winds. I also briefly describe the importance of these
interactions as a possible scenario of high-energy emission from extragalactic
jets.
