Figure 16.

Cumulative loop of Henle bend surface area-to-collecting duct (CD) surface area ratio for all loops (including for each loop the area from the start of the prebend to an equal axial distance on the ascending thin limb). Ratios were determined at 5 μm intervals throughout the final 500 μm of the inner medulla (inner zone 2). This was first done for all native loops (wide-bend plus narrow-bend; open squares). Wide-bend loops were then converted into equivalent narrow-bend loops as described in Pannabecker et al. (2008b), and their three-dimensional surface area was determined. The cumulative loop surface area-to-CD surface area ratio was then computed for all converted wide-bend loops plus all native narrow-bend loops (solid triangles). From Pannabecker et al. (2008b), used with permission.