The role of the kidneys is often underrated when we think about our health.
In fact, the kidneys play a vital role in the daily workings of your body. They are so important that nature gave us two kidneys, to cover the possibility that one might be lost to an injury.
We can live quite well with only one kidney and some people live a healthy life even though born with one missing. However, with no kidney function death occurs within a few days!
How your kidneys work
The kidneys play a major role in maintaining your general health and wellbeing. Think of them as a very complex, environmentally friendly, waste disposal system. They sort non-recyclable waste from recyclable waste, 24 hours a day, seven days a week, while also cleaning your blood.
Most people are born with two kidneys, each one about the size of an adult fist, bean-shaped and weighing around 150 grams each. The kidneys are located at both sides of your backbone, just under the rib cage or above the small of your back. They are protected from injury by a large padding of fat, your lower ribs and several muscles.
Your blood supply circulates through the kidneys about 12 times every hour. Each day your kidneys process around 200 litres of blood. The kidneys make urine (wee) from excess fluid and unwanted chemicals or waste in your blood.
Urine flows down through narrow tubes called ureters to the bladder where it is stored. When you feel the need to wee, the urine passes out of your body through a tube called the urethra. Around one to two litres of waste leave your body each day as urine.
Anatomy of the kidneys
The kidney is not one large filter. Each kidney is made up of about a million filtering units called nephrons. Each nephron filters a small amount of blood. The nephron includes a filter, called the glomerulus, and a tubule.
Blood enters the kidney through the renal artery. The nephrons then work through a two-step process. The glomerulus lets fluid and waste products pass through it. The glomerulus also prevents blood cells and large molecules, mostly proteins, from passing through.
The filtered fluid then passes through the tubule, which sends needed minerals back to your bloodstream and removes wastes. The final product becomes urine. Cleaned blood returns to the body by the renal vein.
This diagram provides a visual introduction to the kidneys. Click on the diagram to view this animation about how your kidneys work.
We acknowledge DaVita for allowing us to use these images as a teaching resource on our website.
The role your kidneys play
Kidneys are the unsung heroes of our bodies and perform a number of very important jobs:
- Blood pressure control – kidneys keep your blood pressure regular.
- Water balance – kidneys add excess water to other wastes, which makes your urine.
- Cleaning blood – kidneys filter your blood to remove wastes and toxins.
- Vitamin D activation – kidneys manage your body’s production of this essential vitamin, which is vital for strong bones, muscles and overall health.
All this makes the kidneys a very important player in the way your body works and your overall health.