BIOL302 Lecture Notes - Lecture 8: Proximal Tubule, Simple Squamous Epithelium, Distal Convoluted Tubule
Document Summary
The urinary system consists of kidneys, ureters, urinary bladder and urethra. Its main function is to remove metabolic wastes and to maintain ionic balance in the circulatory system. Much like the respiratory system it is not really possible to separate the circulatory system from the urinary system. They are intimately tied in both structure and function. The two major functional divisions of the urinary system are 1) the nephron which produces urine and 2) a duct system to convey the urine out of the body. The kidneys are composed of two distinct regions, an outer cortex and an inner medulla. The cortex contains the structures which filter the blood (renal corpuscles) and the initial portions of the duct system. The medulla is composed primarily of straight ducts, giving it a characteristic striated appearance. The medulla is divided into inverted pyramid-shaped sections, with the bases next to the cortex.