Words for north/south and east/west dimensions?

The cardinal axes of the Earth, "North-South" and "East-West", are termed "meridional" and "zonal", respectively.

This usage is particularly common in the atmospheric and earth sciences, where the words are used as adjectives to, for example, describe flow of climate and weather patterns; see for example the Wikipedia article on these terms.

But while these terms are usually used to describe movement, they are also used to describe size and extent; for example:

The zonal extent, meridional extent, and depth of the model are Lx = 4400, Ly = 5500, and H = 4000 meters respectively.

Numerical Methods in Atmospheric and Oceanic Modelling, edited by René Laprise, Charles Augustin Lin, Harold Ritchie

Ok, pursuing the anatomical analogy, I found the words you're looking for: "sagittal dimension" (north-south), "coronal dimension" (east-west), and "transversal dimension" (up-down).

Source: Wikipedia article on anatomical terms of location