The ureter is a muscular tube that connects each kidney to the bladder. It plays a crucial role in the urinary system by transporting urine produced in the kidneys down to the bladder for storage. Each person has two ureters, one for each kidney, and they are about 10 to 12 inches long. The walls of the ureters are lined with smooth muscle, which helps propel urine through peristaltic movements. This ensures that urine flows in one direction, preventing backflow. Proper functioning of the ureters is essential for maintaining the body's fluid balance and waste elimination.