Final answer:
The inner part of the kidney is called the medulla, which is the middle region that contains renal pyramids and papillae for urine transport. The nephron, the functional unit of the kidney, is located in the renal cortex.
Step-by-step explanation:
The inner part of the kidney is known as the medulla. The medulla is the middle region of the kidney situated between the outer cortex and the inner renal pelvis. The renal medulla consists of renal pyramids and renal papillae, which contain collecting ducts that transport urine to the calyces for excretion. The medulla works in tandem with the renal cortex, where all renal corpuscles and the proximal and distal convoluted tubules are located. The renal pelvis is the part of the kidney that collects urine and leads to the ureter, while the nephron is the functional unit of the kidney found in the renal cortex. Nephrons perform the essential functions of filtering blood and generating urine through a series of processes in the coiled tubules and loop of Henle.