Final answer:
The urethra is the urinary system structure that conveys urine from the bladder to the outside of the body. It is unique in exhibiting significant anatomic differences between males and females, unlike the ureter or renal pelvis.
Step-by-step explanation:
The anatomic structure of the urinary system that conveys urine outside the body from the bladder is the urethra. The urethra's main function is to transport urine from the bladder and dispose of it externally. This process is part of the excretion system, which includes other components such as the kidneys, ureters, and bladder. Notably, the urethra is the only part of the urinary system that differs significantly between males and females in terms of anatomy. Unlike the ureter, which connects the kidneys to the bladder, or the renal pelvis, which is part of the kidneys, the urethra is solely responsible for the discharge of urine from the body.