Red blood cells are thus much more common than the other blood particles: there are about 4,000â11,000 white blood cells and about 150,000â400,000 platelets in each microliter of human blood. Human red blood cells take on average 20 seconds to complete one cycle of circulation.
Â­Â­Your kidneys receive the blood from the renal artery, process it, return the processed blood to the body through the renal vein andÂ­ remove the wastes and other unwanted substances in the urine. Urine flows from the kidneys through the ureters to the bladder. In the bladder, the urine is stored until it is excreted from the body through the urethra. Now let's take a look inside your kidneys.
The urea and water are released from the liver cells to the bloodstream and transported to the kidneys where the blood is filtered and the urea is passed out of the body in the urine.Urea is very soluble and a small molecule, so it is relatively easily passed out by the kidneys as a solution in water.xcretion and the liver Excretion in mammals Excretion is the removal of potentially harmful or toxic substances from the body. These substances are usually waste materials produced by complex chemical reactions taking place in living cells. Enzymes catalyse the reactions.