  In the framework of noncompact Kaluza-Klein theory, we investigate a
$(4+1)$-dimensional universe consisting of a $(4+1)$ dimensional
Robertson-Walker type metric coupled to a $(4+1)$ dimensional energy-momentum
tensor. The matter part consists of an energy density together with a pressure
subject to 4D part of the $(4+1)$ dimensional energy-momentum tensor. The dark
part consists of just a dark pressure $\bar{p}$, corresponding to the
extra-dimension endowed by a scalar field, with no element of dark energy. It
is shown that for a flat universe, coupled with the non-vacuum states of the
scalar field, the reduced field equations subject to suitable equations of
state for matter and dark part may reveal inflationary behavior at early
universe, deceleration for radiation dominant era and then acceleration in
matter dominant era.
