Figure 3. Smooth muscle cell (SMC) orientation in intact rat ureter is predominantly longitudinal.

Panel A shows the orientation distribution (3D plot) and the cell density (2D graph) as function of depth, averaged over 36 rat ureter segments. Normalized depth 0 corresponds to the adventitial side of the muscle layer and 1 to the proprial side. At the adventitial side (normalized depth 0 to 0.5) there is a high probability that the angle of the SMCs with respect to the longitudinal axis of the ureter is about 0°. Towards the proprial side the SMC orientation gradually disperses but remains centered around 0°, as further illustrated in panel B by the distributions at four distinct normalized depths (z _n) as indicated. At these depths, standard deviations (σ) are given. In the distribution plot (A) and its top view (C) the curves delimit the octiles of the orientation distribution.