Seperti yang dinyatakan di dalam teks, sternum adalah sisa-sisa kekal di hadapan atau lajur alam semula jadi dari tubuh yang sempurna, -prior kepada "jatuh" pelaku.

Rajah VI-E

Dalam hubungan ini, adalah berguna untuk kutipan dari "Buku Teks Anatomi", edisi ke-4, halaman 767:

Morfologi Sistem Saraf Sympatetik:

“The phylogenetic relation of the sympathetic and the cerebro-spinal elements in the system it is impossible to determine. It may be that the sympathetic system is the representative of an ancient architecture independent of the cerebro-spinal nervous system, the materials of which are utilized for a more modern nervous system; or it may be that the correlation of spinal nerves and sympathetic are both the consequences of the formation of new organs and structures in the splanchnic area. Examined in every light, it possesses features which effectually differentiate it from the cerebro-spinal system, although it has become inextricably united with it and subservient to it.”