What is the middle layer of the kidney called?

• A. Cortex
• B. Medulla
• C. Pelvis
• D. Renal capsule

Answer: (B)

The middle layer is the cortex. The kidney’s outer boundary is the renal capsule, beneath it lies the cortex, and deeper still is the medulla. The cortex contains most of the nephrons—the glomeruli and the proximal and distal tubules—where filtration and early reabsorption occur. The medulla lies deeper and houses the renal pyramids, where urine concentration happens via the loops of Henle and collecting ducts. The pelvis isn’t a separate tissue layer; it’s the central collecting area that funnels urine into the ureter.