Urine drains from the ureters into the bladder through what?

Urine drains from the ureters into the bladder through the ureteral orifices, which are openings located at the base of the bladder. These openings allow urine to flow into the bladder and prevent backflow due to the unique angle and valve-like mechanism of the ureters. This design helps ensure efficient storage of urine until it is expelled from the body during urination.