The kidneys are sophisticated processing machines. Every day, a person's kidneys process about 200 quarts of blood to sift about 2 quarts of waste products and extra water. Waste and extra water become urine, which flows to the bladder through tubes called ureters. The bladder stores urine until releasing it through urination. Wastes in the blood come from the normal breakdown active tissues, such as muscles, and from food. The body uses food for energy and self-repair. After the body has taken what it needs from food, wastes are sent to the blood. If the kidneys did not remove them, these wastes would build up in the blood and damage the body. Removal of actual waste occurs in small units inside the kidneys called nephrons. Each kidney has about a million nephrons. In the nephron, a glomerulus, which is a tiny blood vessel, or capillary-intertwines with a tiny urine collecting tube called a tubule.
The glomerulus acts as a filtering unit, or sieve, and making normal proteins and cells in the bloodstream, allowing extra fluid and wastes to pass through. A complicated chemical exchange occurs, as waste materials and water leave the blood and enter the urinary system. At first, the tubules receive a combination of waste materials and chemicals the body can still be used. Kidney measure chemicals like sodium, phosphorus, and potassium and release them back into the blood to return to tubuh.Dengan this way, the kidneys regulate the body's level of these substances. The right balance is necessary for life.
In addition to eliminating wastes, the kidneys release three important hormones:
- Erythropoietin or EPO, which stimulates the bone marrow to make red blood cells.
- Renin, which regulates blood pressure.
- Calcitriol, the active form of vitamin D, which helps maintain calcium for bones and for normal chemical balance in the body.
Another thing about kidneysPeople with two healthy kidneys have 100 percent of their kidney function. Minor or mild decrease in kidney function-as much as 30 to 40 percent-would rarely seen. Kidney function was calculated using a blood sample and a formula to find the estimated glomerular filtration rate (eGFR). EGFR according to the percent of kidney function available.
Some people are born with only one kidney, but can still live a normal life, and healthy living. Every year, thousands of people donate one of his kidneys for transplantation to a family member or friend.
For many people with reduced kidney function, kidney disease will be present and will get worse. Serious health problems occur when people have less than 25 percent of their kidney function. When kidney function drops below 10 to 15 percent, people need some form of renal replacement therapy, either blood-cleansing treatments called dialysis or a kidney transplant to maintain life.