The document discusses the microstructure of the kidney and ureter. It outlines the main structures of the kidney including the renal capsule, cortex, medulla, renal columns and renal pyramids. It also describes the basic functional unit of the kidney, the nephron, highlighting its key components such as the glomerulus, Bowman's capsule, mesangial cells, and the filtration barrier made of podocytes and their filtration slits.