Urinary System

Urine and Its Formation

What are the main parts of urine production?

The main parts of urine production are glomerular filtration, tubular reabsorption, and tubular secretion. In filtration, blood pressure in the glomerular capillaries forces water and other solutes across the glomerular membrane. The process is similar to what happens in a coffee maker, where water passes through a filter and it carries with it some dissolved compounds (coffee). Usually, the coffee grinds never reach the pot, unless there is a hole in the filter. Reabsorption involves the return of water and major nutrients to the blood. Secretion is the removal of harmful or excess substances from the blood and their transport into the urine.


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