Kidneys are bean-shaped organs, each about the size of our fist. The two kidneys are located in the center if the body, at the back, on either side of the spine. Each Kidney is made up of small complex units called Nephrons. Each kidney contains about 10 lakh nephrons. The Kidneys excrete metabolic waste procedure like urea, creatinine, Hydrogen, Potassium and excess water via urine.
The urine formation occurs in the kidneys round the clock and this formed urine is transported to the collection center called urinary bladder via two drain pipelines called ureters. (refer fig)
At an opportune moment, we can void the urine via the urethra the terminal part of this effluent outlet. A sphincter prevents urine from being passed involuntarily.
The internal morphology of the kidney in a cross-section is also in figure I