The kidney perform internal very complex steps processes to make urine every moment
this urine kept and collected in urinary bladder
on certain volume special sensors in the bladder activated and tell the person to void.
By performing the urine the kidneys perform several invisible functions:
Execrate excess of water
Execrate the waste products such urea and creatinine
Keep electrolyte balance especially for potassium and sodium
Maintain acid base balance by controlling bicarb and hydrogen ions excretions
Execrate different undesirable substances such drugs and other intake substances