Figure 2

Topology and division of the PVS as proposed by Stefanov et al [38]. The division consists in external primo vascular system (ePVS) and internal primo vascular system (iPVS). Structures involved are the receiving primo nodes (rPNs), internal primo nodes (iPNs), communicating primo nodes (cPNs), and organic primo nodes (oPNs). Those nodes are connected by the primo nodes that are connected by the primo vessels (PVs), structures drawn in blue.