Our kidneys ensure that we stay healthy, because they clean our blood. Every day, they filter about 1,800 litres of blood and excrete the filtered waste of products and toxins through urine. It takes just five minutes for all the blood in our body to pass through the kidneys; every day this happens about 300 times. The blood flows back into the heart via the renal vein, and the urine is directed via the ureters into the bladder, where it is collected and finally excreted via the urethra.
Our kidneys tirelessly filter toxins from our blood like a sewage treatment plant.
The filtering systems within the kidney are called nephrons. Our kidneys are made up of a million nephrons. The filter in the nephrons, called the glomerulus, is so fine that only water and small substances pass through. This so-called primary urine, containing salts, nutrients and waste products, is collected in the tubule. 125 millilitres per minute, 180 litres per day. Almost all of the fluid and vital substances such as water, sugar, amino acids and salts are returned to the body in the branched tubule system. Finally, only around 1.5 litres of concentrated urine are excreted.
In addition to detoxification, our kidneys ensure that our blood pressure, water, minerals, acids and alkalis in the body remain within the normal range and that our bones do not become weak.
Larger blood components such as blood cells or proteins are not filtered in the glomerulus and instead are retained in the glomerulus and returned into the bloodstream. In this way, the kidneys regulate the body’s water and salt balance as well as the body pH and blood pressure.
The kidneys produce various hormones. They regulate the production of red blood cells in the bone marrow, and phosphate and calcium metabolism by activating vitamin D, and thus ensure that the bones remain healthy.