Facts I recently found out the , after liver processes metabolites and produce urea and other byproducts , these travel along with the blood to heart and after oxygenation some of it goes to renal artery I.e to kidneys.

Also ,Urea in presence of water decomposes into ammonia which is toxic My questions

1.as mentioned above the chance of urea decomposing into ammonia is high while travelling in the blood (i.e taking long route) but it , still does not happen why?