The Urinary System is a group of organs in the body concerned with filtering out excess fluid and other substances from the bloodstream. The Urinary system includes the following; Two kidneys responsible for formation of urine. Two ureters responsible for the transport of urine to urinary bladder from kidney. Urinary bladder temporary store-house of urine and Urethra.The Urinary system works with the other systems of the body to maintain homeostasis. The kidneys are the main organs of homeostasis because they maintain the acid base balance and the water salt balance of the blood [1].
Kidneys:The paired kidneys are reddish, bean-shaped organs located just above the waist between the peritoneum and the posterior wall of abdomen. Because their position is posterior to the peritoneum of the abdomen cavity, they are said to be retroperitoneal organs. The kidneys are located between the levels of the last thoracic and third lumbar vertebrae, a position where they are partially protected by the eleventh and twelfth pairs of ribs.
a. External anatomy of kidney:Each kidney is 10-12 cm (4-5 in.) long, 5-7 cm (2-3 in.) wide, and 3 cm (1 in.) thick. The lateral surface of the kidney is convex. The medial surface is concave and has a vertical cleft called the renal hilum. The ureters, renal