Urine drains from the nephron into the calyces through which of the following structures?

• A. Proximal convoluted tubule
• B. Glomerulus
• C. Loop of Henle
• D. Collecting duct

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the anatomy of the nephron, which is the functional unit of the kidney. The nephron consists of several structures, including the proximal convoluted tubule, glomerulus, loop of Henle, distal convoluted tubule, and collecting duct.
2. Step 2: Recall the function of each structure in the nephron. The proximal convoluted tubule is responsible for reabsorbing nutrients, ions, and water. The glomerulus is a network of capillaries where filtration of blood occurs. The loop of Henle concentrates urine by reabsorbing water and salts.
3. Step 3: Identify the pathway of urine flow within the nephron. After filtration in the glomerulus, the filtrate passes through the proximal convoluted tubule, loop of Henle, distal convoluted tubule, and finally into the collecting duct.
4. Step 4: Recognize that the collecting duct is the structure where urine is finalized and drained into the renal calyces. The calyces are part of the kidney's drainage system, leading to the renal pelvis and ureter.
5. Step 5: Conclude that the correct answer is the collecting duct, as it is the structure responsible for draining urine into the calyces.