Anatomical plane

[1] In human anatomy, the anatomical planes are defined in reference to a body in the upright or standing orientation.

For the DICOM format, the one imagines a human in the anatomical position, and an X-Y-Z coordinate system with the x-axis going from front to back, the y-axis going from right to left, and the z-axis going from toe to head.

[2] In humans, reference may take origin from superficial anatomy, made to anatomical landmarks that are on the skin or visible underneath.

Examples include: In addition, reference may be made to structures at specific levels of the spine (e.g. the 4th cervical vertebra, abbreviated "C4"), or the rib cage (e.g., the 5th intercostal space).

Hence, what is technically a transverse (orthogonal) section with respect to the body length axis of a rat (dividing anterior from posterior) may often be referred to in rat neuroanatomical coordinates as a coronal section, and likewise a coronal section with respect to the body (i.e. dividing ventral from dorsal) in a rat brain is referred to as transverse.

A necessary note of caution is that modern embryologic orthodoxy indicates that the brain's true length axis finishes rostrally somewhere in the hypothalamus where basal and alar zones interconnect from left to right across the median line; therefore, the axis does not enter the telencephalic area, although various authors, both recent and classic, have assumed a telencephalic end of the axis.

The causal argument for this lies in the end of the axial mesoderm -mainly the notochord, but also the prechordal plate- under the hypothalamus.