“…The governing equations for time-independent transport of oxygen in the tissue and the capillaries, respectively, are given by [18] (1) (2) Here P(x, y, z) is the tissue PO 2 , which is a function of all three coordinates, P i (z) is PO 2 in the ith capillary, D t , is the diffusion coefficient of O 2 in the tissue, α t , is the solubility coefficient of O 2 in the tissue, M is the O 2 consumption rate, Q i is the volumetric blood flow rate, α b is the solubility coefficient of O 2 in the blood, V c is the mean volume of RBC, f i , is the RBC flux (number of cells per second crossing any cross section in the capillary), C Hb is the oxygen-binding capacity of hemoglobin solution inside the cells, Ѱ is the oxygensaturated fraction of hemoglobin, and J i is the O 2 flux from the capillary to the tissue per unit length of the capillary per unit time. The axial diffusion in the tissue has been neglected, which can be justified when the ratio of capillary length to intercapillary distances is sufficiently large [11,29]. For the cases considered in the present paper this ratio is ∼10.…”