KIDNEYS
Where are the kidneys?
While most people have two kidneys that sit on the left and right sides on the inside back wall of the abdominal cavity, there are a few born with one , which because of its appearance is called a horseshoe kidney. It is really two organs that have failed to separate during development.
If you place your hands on your waist with your thumbs pointing forward your spread finger tips will sit over the region of your body under which the kidneys sit. Even though they are protected by an insulating layer of fat, injuries to the area such as a kick from a footy boot can cause damage to one of the organs.
What do they do?
The main function of the kidneys is fluid management and waste disposal. While their action could be described as being like a sieve, the kidneys are much more complex than your colander at home!
1.Fluid and Waste managers
Blood is brought to the kidneys for removal of waste products via large arteries. As the blood passes through filtration occurs – The kidneys are capable of analysing the salt content of blood and changing its concentration by removing excess water if concentration is low or alternatively conserving water if the concentration is high. You can notice your kidney’s at work by the colour of your urine – in the normally functioning pale urine means they are busy getting rid of water, while more yellow urine means they are conserving water.
The Kidneys are also able to assist the body to remove other unwanted substances from the blood. Many drugs are disposed of via the kidneys – some can even be seen – vitamin B causes a characteristic bright neon yellow. Some hormones are excreted via the kidney – an example of how this is useful is the urine pregnancy test where the hormone betaHCG from the placenta can be detected in urine as a screen for pregnancy. In diabetes sugar levels in the blood are high. The kidneys are able to filter out excess sugar – which is why urine testing is helpful in diabetes.
2. Crisis control
The body needs to be able to protect its vital organs in times of crisis and blood pressure management is a key factor in this. In the case of major blood loss obviously circulation would be less efficient and the body recognises the need to conserve the remaining blood flow to vital organs like brain and kidneys. The kidneys have a special detection mechanism in its main arteries that can detect a major drop in blood pressure and release special chemicals into the blood stream which can redirect the flow of blood to protect vital organs. The significance of this mechanism is when people have diseases which affect the blood vessels to the kidneys - narrowing of these vessels through cholesterol being laid down etc may mislead the kidneys into "thinking" the lesser blood flow is indicating a generalised drop in blood pressure and as a result the chemicals are produced and blood pressure generally rises. This becomes a self perpetuating problem., and explains why people with Kidney disease may have associated high blood pressure
3. Blood Cell Producers
The kidneys also play a role in the production of Red Blood Cells. They produce the chemical ERYTHROPOIETIN, which is an active starting ingredient in the production of red cells, the latter being necessary for carrying oxygen to cells. If production is low the kidneys. People with kidney disease may produce less if this chemical and anaemia is a common problem for people with chronic kidney disease.
Kidney problems
The filtration system of the kidneys is very delicate and like a sieve the "holes" are specifically designed to allow some particles and NOT others out of the blood stream and into the urine for waste disposal. Damage to the kidneys can result in failure of the filtration process causing loss of concentration ability or problems with regulation of particle size. The kidney may no longer be able to stop larger particles form escaping . A cardinal sign of kidney disease is protein in urine – there may also be loss of blood cells and other important substances and particles.
Urine is usually sterile. But occasionally bugs may enter the bladder from the outside world. It is possible for these bugs to find their way up the urinary tract to the kidney and the resultant infection can be serious. Symptoms like burning or frequent urge to pass urine should always be investigated by your doctor.
Looking after your kidneys
Myth Busters