The ureters are a pair of thin, muscular tubes that transport urine from the kidneys to the bladder. They are located in the lower back region of the body, and are approximately 25-30 cm long in adults. The ureters are located in the retroperitoneal space, which is the area behind the peritoneum (the membrane that lines the abdominal cavity).The ureters begin at the renal pelvis of the kidney and run downward, crossing the iliac vessels and the ureter crosses the common iliac vessels as it descends towards the bladder. The ureters are located on each side of the bladder and enter the bladder at the ureterovesical junction, which is a ring-like muscle that helps to prevent urine from flowing back into the ureters.The ureters play an important role in the urinary system. They propel urine from the kidneys to the bladder using a process called peristalsis, which is a series of muscular contractions and relaxations that push the urine along the ureter. They also have a specialized muscle called the ureteral muscle, that helps in propelling the urine.The ureters also act as a barrier to prevent the reflux of urine from the bladder back into the kidneys. They have a specialized ring-like muscle called the ureterovesical junction that prevents this reflux by closing tightly when the bladder contracts and opens when the bladder is relaxed.Ureteral obstruction, infection and stones are some of the common issues related to the ureters, they can cause pain and discomfort, and also damage to the kidneys if left untreated.In conclusion, the ureters are a pair of thin, muscular tubes that transport urine from the kidneys to the bladder. They are located in the retroperitoneal space, behind the peritoneum, in the lower back region of the body. They begin at the renal pelvis of the kidney and run downward, crossing the iliac vessels and the ureter crosses the common iliac vessels as it descends towards the bladder, they play an important role in the urinary system such as propelling urine from the kidneys to the bladder, preventing reflux of urine from the bladder back into the kidneys, and act as a barrier. Ureteral obstruction, infection and stones are some of the common issues related to the ureters.