Note that this just produces three parametric equations:
[tex] x(u) = 2 \sin(u)[/tex]
[tex] y(u) = 5 \cos(u)[/tex]
[tex] z(v) = v[/tex]
In the [tex]x-y[/tex] plane, this is just he parametric equation for an ellipse (as a function of u). The z is simply a linear function.
The surface is then an ellipse extruded along the z-axis. We get a elliptic cylinder.