why do we pee?

Question

its not a bad ? its a funny 1

Answer 1

Animals produce nitrogen as a byproduct of living. We excrete this as urea disolved in water (urine).

Answer 2

We pee because of the actions of the kidney.

The kidney has two major roles, removing toxins from the blood (a job it shares with the liver) and controlling the concentration of salt in your blood.

The kidney works by essentially throwing out everything in your blood apart from the blood cells, then re absorbing everything it wants, like water, salts, sugars, etc... This clever process means your kidney can excrete novel chemicals that the liver has no process for destroying. Also, by reabsorbing different amounts of water and salts, your kidney can control the concentration of salts, and the volume of blood, in your body.

All of the chemicals the kidney doesn't reabsorb comes out as pee.