An ==Key Stage 3==[[File:KidneyClipart.png|right|200px|thumb|A drawing of a [[kidney]].]]===Meaning===[[Kidney]]s are [[organ]]s in the [[Excretory System|excretory system]] that removes [[urea]] and excess [[water]] from the [[blood]]. ===About the Kidneys===: The [[kidney]]s are linked to the [[bladder]] by [[ureter]]s.: The [[kidney]]s filter the [[blood]] to remove some [[toxic]] substances. ==Key Stage 4==[[File:KidneyDiagramKS4.png|right|300px|thumb|A [[diagram]] of a [[kidney]] showing the [[nephron]]s.]]===Meaning===[[Kidney]]s are [[organ]] s in the [[Excretory System|excretory system]] that removes [[urea]] and excess [[water]] from the [[blood]]. ===About the Kidneys===: The [[kidney]]s are responsible for [[osmoregulation]] as well as the removal of [[urea]] from the [[blood]].: As [[blood]] passes through the [[kidney]]s [[water]], [[urea]], [[glucose]] and [[salt]]s [[Diffusion|diffuse]] from [[capillaries]] into the kidney tubules at in a structure called a [[nephron]]. [[Glucose]] is completely reabsorbed into the [[blood]] while [[water]] is selectively reabsorbed depending on the [[water]] [[concentration]] in the [[blood]].: The selective re-absorption of [[water]] is affected by [[Anti-diuretic Hormone|anti-diuretic hormone]]. When the levels of [[Anti-diuretic Hormone|anti-diuretic hormone]] are high most of the [[water]] is reabsorbed into the [[blood]]. When the levels of [[Anti-diuretic Hormone|anti-diuretic hormone]] are low the [[water]] is not re-absorbed and is passed down the [[ureter]]s to the [[bladder]]. ===Extra Information==={{#ev:youtube|https://www.youtube.com/watch?v=FN3MFhYPWWo}} ===References=======AQA==== :[https://www.amazon.co.uk/gp/product/1471851338/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851338&linkCode=as2&tag=nrjc-21&linkId=425855d5890466e47189e1c21b67a1ea ''Kidneys, pages 155-8, GCSE Biology, Hodder, AQA '']:[https://www.amazon.co.uk/gp/product/0198359373/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0198359373&linkCode=as2&tag=nrjc-21&linkId=952a73bbb09d222ecc4b50d200679849 ''Kidneys, pages 186-191, GCSE Biology; Third Edition, Oxford University Press, AQA '']:[https://www.amazon.co.uk/gp/product/1782945954/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945954&linkCode=as2&tag=nrjc-21&linkId=100574c08fbbb64318256eb79ed61a76 ''Kidneys, pages 215, 219-221, GCSE Biology, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945563/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945563&linkCode=as2&tag=nrjc-21&linkId=9a1d023a374038e6072f33c4f3cf808b ''Kidneys, pages 75, 76, GCSE Biology; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945954/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945954&linkCode=as2&tag=nrjc-21&linkId=100574c08fbbb64318256eb79ed61a76 ''Kidneys; kidney failure, pages 219, 220, GCSE Biology, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945954/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945954&linkCode=as2&tag=nrjc-21&linkId=100574c08fbbb64318256eb79ed61a76 ''Kidneys; kidney transplants, pages 220, 221, GCSE Biology, CGP, AQA ''] ====Edexcel==== :[https://www.amazon.co.uk/gp/product/1292120207/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120207&linkCode=as2&tag=nrjc-21&linkId=22455ff53961978667722edaa64c0be5 ''Kidneys, pages 156, 158-159, GCSE Biology, Pearson, Edexcel '']:[https://www.amazon.co.uk/gp/product/1782948120/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782948120&linkCode=as2&tag=nrjc-21&linkId=dedef775c6a43dbb0a609441525adac0 ''Kidneys, pages 246-248, 250, 251, GCSE Biology, CGP, Edexcel '']:[https://www.amazon.co.uk/gp/product/1782946748/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782946748&linkCode=as2&tag=nrjc-21&linkId=a4f0348fc37d0ba1bb52d27f8679581f ''Kidneys, pages 84, 85, GCSE Biology; The Revision Guide, CGP, Edexcel ''] ====OCR====:[https://www.amazon.co.uk/gp/product/0198359810/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0198359810&linkCode=as2&tag=nrjc-21&linkId=d768d99f1a06f7c12fab40e5aef85a55 ''Kidneys, pages 120-124, 242, Gateway GCSE Biology, Oxford, OCR '']:[https://www.amazon.co.uk/gp/product/1782945660/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945660&linkCode=as2&tag=nrjc-21&linkId=83aa4500ad7759e7f401a1c5ba5df758 ''Kidneys, pages 54, 55, Gateway GCSE Biology; The Revision Guide, CGP, OCR '']