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How does the angle where a ureter enters the bladder help prevent urine from flowing backward?
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renal system
Diagram showing the location of the kidneys in the abdominal cavity and their attachment to major arteries and veins.
The ureters enter the urinary bladder at an oblique angle, passing through the bladder wall in a specific manner. As the bladder fills with urine, the increasing pressure compresses this terminal portion of the ureter. This mechanical compression acts as a functional valve, effectively closing the tube and preventing the backflow of urine toward the kidney.1