The Kidneys

• Kidneys act as filters to clean the blood
• The kidneys make urine by taking waste products out of your blood
• Substances are filtered out of the blood as it passes through the kidneys = filtration
• Glucose, some ions and the right amount of water are absorbed back into the blood = selective reabsorption
• Substances removed from the urine:

  .Urea

  .Ions

  .Water
• Concentration of urine is controlled by an anti-diuretic hormone which is then released into the bloodstream by the pituitary gland
• Whole process of water regulation is controlled by negative feedback = meaning if water gets too high or low, negative feedback is triggered to bring it back to normal