Renal Cross-sectional Anatomy

The Renal Cross-section
  • Renal Cortex
    • The renal cortex lies under the capsule of the kidney. It contains the top portion of the nephrons (i.e. the glomerulus as well as proximal and distal tubules).
  • Renal Medulla
    • Is subdivided into cone-shaped renal pyramids, the outer portion of which border the renal cortex and the inner tip of which empty into the minor calyces. The minor calyces combine into the major calyx which is continuous with the ureter.
    • Each renal pyramid contains the lower portion of the nephron (i.e. thin loop of Henle, thick ascending loop of Henle, and collecting duct).
Urine Flow
  • Urine is considered to be the fluid left at the end of the nephron when all resorptive and secretory activity is complete. It is thus considered to be the fluid leaving from the tip of each renal pyramid. It is subsequently collected into the minor calyces and then into the major calyx after which it enters the ureter.