Which structure is a hindgut derivative that contributes to the urinary system?

Which structure is a hindgut derivative that contributes to the urinary system?

• A. Descending colon
• B. Epithelium of urinary bladder
• C. Right part of transverse colon
• D. Sigmoid colon

Answer: (B)

The key idea is that the urinary bladder epithelium comes from endoderm of the urogenital sinus, which itself is formed from the cloaca. The cloaca is the shared region at the end of the hindgut that gets divided by the urorectal septum into a ventral urogenital sinus (which forms the bladder and parts of the urinary tract) and a dorsal anorectal canal. So, the epithelium lining the urinary bladder is a hindgut-derived tissue that participates in the urinary system. The other structures listed—portions of the colon such as the descending, transverse, and sigmoid colon—are indeed hindgut derivatives but they form only parts of the digestive tract and do not contribute to urinary tissues.

The key idea is that the urinary bladder epithelium comes from endoderm of the urogenital sinus, which itself is formed from the cloaca. The cloaca is the shared region at the end of the hindgut that gets divided by the urorectal septum into a ventral urogenital sinus (which forms the bladder and parts of the urinary tract) and a dorsal anorectal canal. So, the epithelium lining the urinary bladder is a hindgut-derived tissue that participates in the urinary system. The other structures listed—portions of the colon such as the descending, transverse, and sigmoid colon—are indeed hindgut derivatives but they form only parts of the digestive tract and do not contribute to urinary tissues.