Which of the following statements about the urinary system is incorrect?

• A. Papilla in the kidney open into calyces which are continuous with the renal pelvis.
• B. The urinary bladder is composed of 3 layers of smooth muscle and lined by mucous membrane.
• C. Filtration of blood in the renal corpuscle produces a filtrate that is further processed in the renal tubule.
• D. The indented medial surface of the kidney gives way to the ureters that open into the urinary meatus.

Answer: (D)

Verified step by step guidance

1. Step 1: Review the anatomy of the kidney, focusing on the medial surface and its structures. Understand that the medial surface contains the renal hilum, where structures such as the renal artery, renal vein, and ureter enter or exit the kidney.
2. Step 2: Analyze the statement about the papilla in the kidney opening into calyces, which are continuous with the renal pelvis. Confirm that this is correct because the renal papillae drain urine into minor calyces, which join to form major calyces, leading to the renal pelvis.
3. Step 3: Examine the structure of the urinary bladder, noting that it is composed of three layers of smooth muscle (the detrusor muscle) and lined by a mucous membrane (urothelium). This confirms the accuracy of the second statement.
4. Step 4: Understand the process of filtration in the renal corpuscle, where blood plasma is filtered to form filtrate, which then passes through the renal tubule for further processing. This validates the third statement as correct.
5. Step 5: Identify the incorrect statement by recognizing that the ureters do not open into the urinary meatus. Instead, the ureters transport urine from the kidneys to the urinary bladder, and the urinary meatus is the external opening of the urethra, not connected directly to the ureters.