Kidneys Filter Your Entire Blood Supply Many Times a Day
A kidney filters waste from blood. The scale of the work is far greater than the organ's size suggests.
A kidney is one of a pair of organs that filter waste from the blood. The workload is remarkable for organs the size of a fist: they process around 180 litres of filtrate a day and return almost all of it, producing only a litre or two of urine. The whole blood supply passes through them many times each day.
- A filtering organ. *A kidney transplant.*
- Kind or type (dated). *A man of that kidney.*
- Kidney bean — a red bean. *Chilli with kidney beans.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | kidney | The left kidney. |
| Plural | kidneys | Both kidneys. |
| Adjective | renal | Renal failure. |
| Related | nephron | A single nephron. |
| Field | nephrology | A nephrology unit. |
How it is used in a sentence
- Dialysis replaces kidney function.When the organs fail.
- A man of the same kidney.Archaic: of the same character.
- Renal and nephro- both mean kidney.From Latin and Greek.
What kidneys do
- Filter waste — through about a million nephrons each
- Regulate fluid — controlling how much water is retained
- Balance electrolytes — sodium, potassium and others
- Control blood pressure — through the renin system
- Produce hormones — including one that triggers red blood cell production
From Middle English *kidenei*, of uncertain origin. The second element may be *ei*, an egg, describing the shape.
Can you live with one kidney?
Yes. A single healthy kidney can do the work of two, which is why living donation is possible.
Why are renal and nephrology different words?
Renal comes from Latin *ren*, nephrology from Greek *nephros*. Medicine draws on both languages for the same organ.