Rabbit kidney.
Same histology section as that of picture 15 (longitudinal section) showing in addition, at the bottom, a cross section of a medullary ray at a higher magnification.
Four collecting ducts are visible (C) surrounded first by thick ascending limbs (which have a relatively thin epithelium in the cortex) and more peripherally, by the (descending) pars recta of proximal tubules.
L. Bankir, N. Bouby, MM Trinh-Trang-Tan and B. Kaissling.
Actualités Néphrologiques de l'Hôpital Necker (Editeur JP Grünfeld), Flammarion Médecine-Sciences, 1986, pp. 66-69. Or/ou Advances in Nephrology (JP Grünfeld Editor), Year Book Medical Publishers, 1987, pp. 69-102