Nephrons are tiny tubules (miniature tubes) which make up the smallest working part of the kidney. In other words, they are the smallest level where the kidney removes waste, excess salt and excess water. Each nephron starts in the cortex of the kidney, then goes into the medulla of the kidney, before coming back to the cortex, then goes through the medulla into the pelvis. In the pelvis, the nephrons join up with the ureter.
In humans, a normal kidney has between 800,000 and 1.5 million nephrons.
Each nephron consists of a cup-shaped structure at one end called the Bowman's capsule. It extends into a long urinary tubule,that is surrounded by a network of renal capillaries. The urinary tubules of nephrons in each kidney join to form a common tube called the ureter.
Inside the Bowman's capsule,is a network of blood capillaries called glomerulus. The Bowman's capsule and glomerulus together form the Malphigian capsule or Malphigian body.