Anti aging guide

Kidney and Aging

 

 

Why our kidneys are exposed to damage by common disease?

Each minute rather more than a liter of blood is pumped through the kidneys and about a tenth of it passes through the 650 000 miniscule filters or glomeruli into the tubules which eventually lead to the collecting system and the bladder. In a fit, young person, this means that about 130 ml of plasma are processed and enter the tubules each minute, although eventually only around 1 ml of urine is produced each minute, the remainder of the water being reabsorbed into the circulation. The amount of urine production, the quantity of water eliminated from the blood stream, and the composition of the urine in terms of salt, potassium, and other elements are manipulated by the tubules in such a way as to keep the body’s balance under precise regulation. Each glomerulus and its tube is called a nephron, and conventional wisdom has it that by the time we reach 80, half of them have been lost, so the quantity of plasma processed per minute is halved. Despite this, it is also widely accepted that 80-year-olds are more prone to dehydration because the tubules they still have are much less capable of returning water to the blood stream and they will continue to produce large quantities of urine even if they do not drink much fluid. However they also have difficulty eliminating surplus water, salt, and waste products such as urea.

As we pass through life our kidneys are exposed to damage by atherosclerosis and especially by high blood pressure, as well as diabetes and cystitis and many other common diseases. The generally accepted view of declining renal function may be very misleading, as it includes subjects with well-defined common disorders, and a third of people probably do not show this steady decline in renal function with the passage of the years.

Posted by Carol Hudgens - April 27, 2012 at 11:19 am