Trigone of urinary bladder develops from:
**Core Concept**
The trigone of the urinary bladder is a triangular area located at the base of the bladder, formed by the two ureteric orifices and the internal urethral orifice. It is a distinct anatomical region that plays a crucial role in the bladder's function. The trigone is derived from the mesoderm, specifically the cloacal membrane, during embryonic development.
**Why the Correct Answer is Right**
The trigone develops from the caudal portion of the cloacal membrane, which is a thickened plate of mesodermal cells that forms during embryonic development. As the embryo grows, the cloacal membrane gives rise to the trigone, which is then divided into the two ureteric orifices and the internal urethral orifice. The trigone's development is closely tied to the formation of the bladder and the ureters.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the trigone does not develop from the urogenital sinus.
* **Option B:** This option is incorrect because the trigone does not develop from the paramesonephric ducts.
* **Option C:** This option is incorrect because the trigone does not develop from the mesonephric ducts.
**Clinical Pearl / High-Yield Fact**
The trigone is a unique area of the bladder that is devoid of smooth muscle, making it less susceptible to detrusor overactivity and bladder instability. This characteristic is essential to remember when diagnosing and managing lower urinary tract symptoms.
**Correct Answer:** C. Mesonephric ducts.