The ureters are retroperitoneal tubes located on either side of the vertebral column. They are responsible for transporting urine from each kidney to the urinary bladder. These tubes have thick walls and are approximately 25-30 cm long. Their diameter is around 10 mm at the renal pelvis, gradually narrowing to 1 mm as the ureter obliquely enters the posterior bladder wall through the ureteric orifices. The shape of these orifices is slit-like, which helps to prevent urine backflow toward the...

The function of the kidneys is to filter, reabsorb, secrete, and excrete. Every day the kidneys filter nearly 180 liters of blood, initially removing water and solutes but ultimately returning nearly all filtrates into circulation with the help of osmoregulatory hormones. This process removes wastes and toxins but is also crucial to maintain water and electrolyte levels. Most of these functions are performed by the tiny but numerous nephrons contained within the kidneys.