The triangular area bounded by the urethral openings and the entrance to the urethra constitutes the ________.
A) external urethral sphincter
B) detrusor muscle
C) internal urethral sphincter
D) renal sinus
E) trigone

Question

Quizplus · Accepted Answer

The triangular area bounded by the urethral openings and the entrance to the urethra is called the trigone. It is an important landmark in the urinary system as it is where the internal urethral sphincter is located and is also the most sensitive area to detect the sensation of bladder fullness, which triggers the micturition reflex. The external urethral sphincter is a skeletal muscle under voluntary control, while the detrusor muscle is the smooth muscle responsible for bladder contraction. The renal sinus is an internal cavity within the kidney housing the renal pelvis and blood vessels.

The Triangular Area Bounded by the Urethral Openings and the Entrance