Hi Maha
Is it possible to change the orientation of lines?
No - well unless you are sneaky
What you are looking at is a glimpse of the underlying mathematics of the surface -the uv curves
How they work is way above me. I suggest you try looking at the curves from various sorts of surfaces and this will give you an insight.
Cone
Cylinder
Sphere
Helical
Extrusion
Have a play.
So how was I sneaky?
simples - I rotated the body
As a bonus..
try untrimming a diamond
It looks like a coordinate system?