  Classical T Tauri stars are pre-main-sequence objects that undergo
simultaneous accretion, wind outflow, and coronal X-ray emission. The impact of
plasma on the stellar surface from magnetospheric accretion streams is likely
to be a dominant source of energy and momentum in the upper atmospheres of
these stars. This paper presents a set of models for the dynamics and heating
of three distinct regions on T Tauri stars that are affected by accretion: (1)
the shocked plasmas directly beneath the magnetospheric accretion streams, (2)
stellar winds that are accelerated along open magnetic flux tubes, and (3)
closed magnetic loops that resemble the Sun's coronal active regions. For the
loops, a self-consistent model of coronal heating was derived from numerical
simulations of solar field-line tangling and turbulent dissipation. Individual
models are constructed for the properties of 14 well-observed stars in the
Taurus-Auriga star-forming region. Predictions for the wind mass loss rates
are, on average, slightly lower than the observations, which suggests that disk
winds or X-winds may also contribute to the measured outflows. For some of the
stars, however, the modeled stellar winds do appear to contribute significantly
to the measured mass fluxes. Predictions for X-ray luminosities from the shocks
and loops are in general agreement with existing observations. The stars with
the highest accretion rates tend to have X-ray luminosities dominated by the
high-temperature (5-10 MK) loops. The X-ray luminosities for the stars having
lower accretion rates are dominated by the cooler accretion shocks.
