The functional tissue of the kidney composed of the nephrons is called

• A. Renal parenchyma
• B. Renin
• C. Renal sinus lipomatosis
• D. Pelviectasis

Answer: (A)

Nephrons are the microscopic functional units of the kidney, and the tissue that contains them is the renal parenchyma. This functional tissue makes up the bulk of the kidney and includes both the cortex and medulla, where glomeruli in the cortex and the tubules and collecting ducts extending into the medulla carry out filtration, reabsorption, and secretion to form urine. The other terms describe different structures or substances: renin is an enzyme/hormone produced by juxtaglomerular cells, renal sinus lipomatosis is fat within the renal sinus, and pelviectasis is dilation of the renal pelvis. Thus, the functional tissue composed of nephrons is renal parenchyma.