Slide 14 Collecting Duct
The collecting duct, shown here in a longitudinal section, is composed of simple cuboidal epithelium. Notice the prevalence of nuclei. Below are intermediate tubule segments (a.k.a., thin limbs of loop of Henle) and vasa rectae (with RBCs) both have a simple squamous epithelium.

Bar = 50 Microns

Expanded View