Slide 5 Collecting Ducts - Outer Medulla
The collecting ducts have simple cuboidal epithelia as do some of the other tubule segments in this low magnification field. Notice that a group of blood vessels called vasa rectae (arrows) on the right parallel these tubules running into the medulla. Remember that ther are no arteries/arterioles supplying blood to the medullary structures, only the vasa rectae. Where do the vas rectae come from?

Bar = 250 Microns

Expanded View