Network Arteriolar

Arteriogenesis is the growth of collateral vessels from a pre-existing arteriolar network to bypass an ischemic area (e.g., following cardiac ischemia). 

Figure 9. Schematic representation of the arteriolar network to test the extended Darcy equation. Two pressure distributions P, and P2 are chosen, (pressures in kPa), diameters in um. Shaded area compartment with —115

The normal coronary system consists of large epicardial or surface vessels (Rj) that offer little resistance to myocardial flow and intramyocardial arteries and arterioles (R2), which branch into a dense capillary network to supply basal blood flow (Fig. 11-1). Under normal circumstances, the resistance in R2 is much greater than that in Rj. Myocardial blood flow is inversely related to arteriolar resistance and directly related to the coronary driving pressure. 

Arteriolar and Venular Blood Flow Microvascular Networks Structure and Hemodynamics... 

It has also been established that the RBC itself could act as a mobile sensor for hypoxia [61]. The mechanism works as follows Under conditions of low oxygen and pH, the RBC releases ATP, which binds to purinergic receptors on the endothelial cells. This leads to the production in the endothelial cells of the vasodilator NO. Since the most likely location for hypoxia would be in or near the venular network, the local vasodilatory response to NO is propagated to upstream vessels causing arteriolar vasodilation (see the following section on Coordination of Vasomotor Responses). 

---