The outer region of the kidney is called the cortex.
The cortex is the layer that surrounds the inner part of the kidney, known as the medulla. It plays a crucial role in the kidney’s function, as it contains the renal corpuscles and a significant portion of the nephrons, which are the basic functional units of the kidney. The cortex is responsible for filtering blood and producing urine by regulating the levels of various substances in the body, including electrolytes and water. Understanding the structure of the kidney helps in comprehending how it maintains fluid balance and removes waste from the bloodstream.