This week's focus was the kidney, an important organ whose main role is to filter the blood to generate urine. We can live without one kidney, but not without two. They are located in the abdominal cavity near the organs of the digestive tract, but they are part of the urinary system, not the digestive system.
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| This is the machine for dialysis |
The process of breaking down food to get the nutrients leads to waste products, including urea. If these waste products are not cleaned out of the blood, we will die. When someone's kidneys are not functioning well, he or she must go on dialysis to survive. Dialysis involves being hooked up to a machine that takes out some of your blood, cleans and filters it, then puts back the filtered blood. It is not as good as your kidneys, but if you go for dialysis often enough (typically at least 3 times a week for several hours), you can survive for a long time without functioning kidneys.
Kidneys make sure that sugar does not get into the urine, and a sign of kidney infection is when a test shows sugar in the urine. However, more commonly when sugar is in the urine, there is a problem with blood sugar regulation, such as diabetes.
The structures inside kidneys that filter the blood are called nephrons, and people have about a million tiny nephrons in their bodies. Inside the nephrons are glomeruli, little bundles that pass the blood through tiny tubes to get waste products such as urea out of it. The urine created by adding the waste products to water then drips down into the bladder.
Blood goes to the kidneys from the renal artery, and all our blood passes through the kidneys twelve times per hour on average. Filtered blood goes back to the heart through the renal vein. Waste products build up in the blood very quickly when the kidneys are not working, and this can be detected through tests.
