Reimagining systematic anatomy: The conclusion of the quartet.

Abstract

The central dogma of systematic anatomy is the well-known hierarchy of anatomical structures: body-systems-organs-tissues-cells. This schema omits extracellular matrix and extracellular fluids, which account for a significant proportion of body mass, and distorts the meanings of the terms system, organ and tissue in anatomy. These faults are partially due to oversimplification, presumably intended for educational purposes, and confusion of anatomy's organ systems with physiological systems. A revised schema of the hierarchy of systematic anatomy is presented that is more complete and more consistent with the long history of anatomy.