The Urinary System is the body’s drainage system for removing urine, which is made up of wastes and extra fluid. For normal urination to occur, all body parts in the urinary tract need to work together, and in the correct order. The urinary system includes two kidneys, two ureters, a bladder, and a urethra.

The kidneys are paired retroperitoneal organs of the urinary system. Their function is to filter blood and produce urine. Each kidney consists of a cortex, medulla and calyces. The nephron is the main functional unit of the kidney, in charge of removing metabolic waste and excess water from the blood. In this article we will explore the microanatomy of a nephron and learn how their function relates to their histological features.

The ureter is a muscular tube, composed of an inner longitudinal layer and an outer circular layer of smooth muscle. The lumen of the ureter is covered by transitional epithelium (also called urothelium).Its ability to stretch allows the dilation of the conducting passages when necessary. The ureter connects the kidney and the urinary bladder.