The discovery of the excretory function of the kidney.


The kidney is one of the two bean-shaped organs that filters the blood, excreting the end-products of body metabolism in the form of urine. The kidneys are the major regulators of water, electrolytes, acid-base content of the blood and indirectly, all body fluids[1].


The Greek surgeon and philosopher discovered[2] the excretory function of the kidney after performing an experiment on an animal (most likely a monkey). The experiment is as follows:

  • He ligatured (tied up) the ureters (the ducts that carry urine away from the kidneys to the bladder) of a live animal and let it go otherwise it would not urinate.
  • After reopening the animal, he observed the ureters as distended to the point of rupturing. He also noticed an empty bladder.
  • After removing the ligatures, he saw the bladder slowly getting filled with urine from the ureters.

Here is a portrait[3] of Galen:

[ux_image_box img=”1199″ image_width=”40″ link=”” target=”_blank”]

129-circa 210


  2. mode/2up, pages 59 and 61.
  3. PIIS0140-6736%2812%2960846-0/fulltext

Leave a Comment

Your email address will not be published. Required fields are marked *