Normally, Urine produced by healthy kidneys is a cocktail of toxic waste products of cellular metabolism, a host of minerals, salts, smelly organic compounds & excess water. (Find the complete normal urine composition here). These components begin to get together to form Urine once healthy kidney micro-filters “strain” our blood through themselves. These micro-filters are uber-selective with what they “let-out” into the urine. This is such that, all blood cells & “plasma” proteins remain in the bloodstream while the wastes & excesses purge themselves out.
But what makes these Kidney Micro-filters that selective against leakage of blood cells & protein in urine?