10 interesting facts about your kidneys

10 interesting facts about your kidneys

Have you ever wondered where your kidneys actually are? Or if you can survive with just one kidney?

Do you know what the hieroglyphic for wee is?

Read this article to find out the answers and learn many more interesting and strange facts about the kidneys!

1. Your kidneys are located near the middle of your lower back, on either side of your backbone (spine)

People tend to think they are on the sides of the tummy. They are not. They are about the size of your palm: 12 (10-14) cm long, 6 cm wide and 3 cm deep, and weigh 150g.

The location of the kidneys in a human adult

Click here to find out more about where your kidneys are located

2. The Ancient Egyptians knew a lot about kidneys. Have a look at the Ebers Papyrus (1550 BC)

You can see hieroglyphic inscriptions representing the various Egyptian terms for urine.

Ebers Papyrus (1550 BC)

3. The kidneys are part of the urinary tract and each contain about 1 million glomeruli (filtering units, i.e. tiny sieves)

In other words, the entire organ is not one big filter. It is a million tiny ones. Its main purpose is to filter the blood of waste and excess water and remove them from the body in the urine. Click here to find out more about the kidneys’ functions.

This diagram shows urinary tract

This cartoon shows a glomerulus (small filtering unit) within the kidney

4. The first six human kidney transplants took place in Ukraine – carried out by Dr Yu Yu Voronoy (1895-1961)

He was working in an obscure part of the Ukraine, between 1933 and 1949. The kidneys were transplanted into the thigh! He published in an obscure journal too …

Part of Voronoy’s publication in El Siglio Medico, 1936

5. All kidney functions can be carried out by a single kidney. In fact 1 in 1000 people are born with one kidney and have few issues

6. The world’s largest kidney stone – was removed from a patient in Sri Lanka. It was about the size of a grapefruit

At 13.4 cm and weighing 801 grams, it was removed by Sri Lankan Army doctors on June 1, 2023.

The world’s largest kidney stone

7. About 180 litres of blood are pumped from your heart through the kidneys every day

A normal adult human has 5 litres of blood in their bodies – this means the blood is filtered and cleaned 35x a day! Even though 180L are filtered, most of that liquid is put back (reabsorbed) into the blood. This means only 2L of urine are produced each day.

Even though the kidney only accounts for 0.5% of the body’s weight on average, it receives more blood (20% of the cardiac output) than all other organs except the liver.

8. A Dutch doctor used sausage casing, orange juice cans, and a washing machine to make the first ‘artificial kidney’ during World War II

Dutch doctor Willem Kolff invented an artificial kidney from these simple parts. This evolved into modern-day haemodialysis.

The first artificial kidney created by Dr Willem Kolff

9. Some athletes – especially cyclists and long distance runners – take a kidney substance called erythropoietin (EPO). They should not

EPO is a hormone usually made by the kidney. EPO stimulates the bone marrow to make red blood cells. More red blood cells, means the blood can carry more oxygen. This can improve athletes’ performances. However, it is not sensible as it carries significant risk.

10. Mammals empty their bladders on average for 21 seconds

.. despite a difference in bladder volume from 0.15 ml (mouse) and 300 ml (human), to 18 L (elephant) and 300 L (blue whale). This is called the Law of Urination.

[“It’s amazing what you can learn here about elephants peeing”. CKDEx Ed]

Summary

We have described 10 interesting facts about your kidneys. We hope it has been useful.

Click here to learn more facts about the kidneys