A longitudinal plane is any plane perpendicular to the transverse plane.

 

The coronal (frontal) plane, the midsagittal plane and the parasagittal plane are all examples of a longitudinal plane.

 

An Oblique Plane is a trans-section of the body occurring at an angle to one of the three major planes. 

 

An oblique plane can run at an angle to a longitudinal plane or a transverse plane.