While your body is working hard to provide you with all your needs, it is also producing wastes. Wastes are harmful to the body if they are allows to accumulate, so we need an efficient system to get rid of them. Your kidneys are part of this system.

There are 6 ways that the body gets rid of waste:

• Defecation- removing waste from the digestive tract
• Lungs- breathing out carbon dioxide and water as waste
• Liver- Proteins are digested into amino acids. Amino acids cannot be stored in our body so the liver breaks down amino acids down into a substance called urea.

Poisonous substances may enter the body from the digestive tract . These are carried to the liver, where they are broken down into harmless substances. The harmless substances are then returned to the blood and from there they pass to the kidneys.

The liver breaks down old red blood cells. Any unwanted hemoglobin is added to bile and passes with the bile into the intestines.

• Skin- there are millions of chemical reactions happening inside of your cells. These chemical reactions can produce heat. Our body’s core temperature must be kept around 37˚C. In order to get rid of excess heat, or skin releases heat
• Kidneys

The kidneys excrete urea which is a waste product when proteins are broken down. The kidneys also control the level of water in the body.

When your body is well supplied with water, dilute urine is produced.

The urine is clear or pale yellow in color. IF you body has little water, then the kidneys take out only a small amount of water. This produces concentrated urine with a strong gold color

Your kidneys also control salt levels in the blood. Too much or too little salt in the blood prevents cells from working correctly. So it is very important that the concentration of salts is controlled. Excess salt is removed in the urine.

Urine

Urine is the waste material that has been filtered out of the blood by the kidneys. On average, urine is 95% water. The other 5% is urea, with small amounts of salts and pigment.

The pigment comes from the breakdown of hemoglobin and gives urine its yellow color.

Urine passes from the kidneys down narrow tubes called ureters and into the bladder, where it is stored. The bladder is a muscular bag. It can expand to hold about 500mL of urine.

The urethra is a tube that carries the urine to the outside of the body. At the end of the urethra is a sphincter muscle that controls the emptying of the bladder.

Together, the kidneys, bladder, ureters and urethra are called the urinary tract.

Kidney disease

More than 500 000 Australians a year consult their doctors about kidney disease and urinary tract infections. High blood pressure, kidney stones and infections are some of the causes.

High blood pressure

Your blood travels a relatively short distance to your kidneys. very little pressure from the heartbeat is lost, so blood entering the kidneys is under pressure. This pressure helps the filtering process carried out by the kidneys.

However, an abnormally high blood pressure can easily damage the fragile capillaries where the blood is filtered. This affects the functioning of the kidneys.

Kidney stones

Kidneys stones occur when chemical normally present in the urine combine to create hard crystals. FI they are small enough the crystals will pass out of the kidneys with the urine. However larger stones can block the fine tune tubes within the kidney, causing pain and preventing the flow of urine.

Large kidneys stones may have to be removed in an operation but more commonly they are shattered into tiny pieces using ultrasound waves. the smaller pieces should then pass naturally from the body.