Kidney stained with Masson?檚 trichrome, light micrograph. This is the inner stripe of the outer renal medulla. There are numerous cross-sectioned tubules, of which two major morphological types can be distinguished. The first, larger type, is lined by a simple cuboidal epithelium without a brush border. They are distal convoluted tubules and, to a lesser extent, collecting ducts. At this magnification, the distinction is very difficult. The second type are extremely thin-walled canals, with a very thin epithelium. They are loops of Henle and also capillaries. As the latter do not have blood inside, they cannot be distinguished from the loops of Henle.