Supracellular structural principle of multicellular organisms.

All the supracellular structures composed of compact aggregates of constituent units are subordinate to a single structural principle. It is a particular space division called equilibrium space division (ESD) by the author. EDS is a geometrical expression of the second law of thermodynamics corresponding to a state of minimized potential energy of the system of constituent units assembled by uniform or polarized centripetal force. It is a statistical process under incomplete mechanical restrictions and cannot entirely be reduced to deterministic mechanisms. Supracellular structures are accordingly not directly prescribed by genetic information based upon the template function of DNA molecules. Blood vessels are essentially localized on the edges of ESD, so that their geometry is influenced by this particular space division. Some geometrical parameters of arteries are theoretically derived from the geometry of ESD, partly with the aid of a model of space division by uniform beta-tetrakaidecahedra, which approximately replaces ESD.