In the collecting ducts, the fluid may remain dilute, or water can be absorbed from the fluid and returned to the blood, making the urine more concentrated. Water reabsorption is regulated by antidiuretic hormone produced by the pituitary gland and other hormones. These hormones help to regulate kidney function and control urine composition to maintain body water and electrolyte balance Overview of Electrolytes Well over half of the body's weight is made up of water.
Doctors think about the body's water as being restricted to various spaces, called fluid compartments. The three main compartments are As the body metabolizes food, certain waste products are created, and these products need to be removed from the body. One of the main waste products is urea, which comes from protein metabolism. Urea passes freely through the glomerulus into the tubular fluid and, because it is not reabsorbed, is passed into the urine.
Other undesirable substances, including metabolic waste products such as acids, and many toxins and drugs, are actively secreted into the urine by cells in the renal tubule and give urine its characteristic odor. Another function of the kidneys is to help regulate the body's blood pressure by excreting excess sodium. If too little sodium is excreted, blood pressure is likely to increase. The kidneys also help regulate blood pressure by producing an enzyme called renin. When blood pressure falls below normal levels, the kidneys secrete renin into the bloodstream, thereby activating the renin-angiotensin-aldosterone system Regulating Blood Pressure: The Renin-Angiotensin-Aldosterone System High blood pressure hypertension is persistently high pressure in the arteries.
Often no cause for high blood pressure can be identified, but sometimes it occurs as a result of an underlying The kidneys also produce urotensin, which causes blood vessels to constrict and helps raise blood pressure.
A person with kidney failure is less able to regulate blood pressure and tends to have high blood pressure. Through the secretion of hormones, the kidneys help regulate other important functions, such as the production of red blood cells and the growth and maintenance of bones. The kidneys produce a hormone called erythropoietin , which stimulates the production of red blood cells in the bone marrow. The bone marrow then releases red blood cells into the bloodstream.
Growth and maintenance of healthy bones is a complex process that depends on several organ systems, including the kidneys. The kidneys help regulate levels of calcium and phosphorus, minerals that are critical to bone health. They do so by converting an inactive form of vitamin D , which is produced in the skin and is also present in many foods, to an active form of vitamin D calcitriol that acts like a hormone to stimulate absorption of calcium and phosphorus from the small intestine.
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Functions of the Kidneys. If you are in one of these groups or think you may have an increased risk for kidney disease, ask your doctor about getting tested. Many kidney diseases can be treated successfully. Careful control of diseases like diabetes and high blood pressure can help prevent kidney disease or keep it from getting worse.
Kidney stones and urinary tract infections can usually be treated successfully. Unfortunately, the exact causes of some kidney diseases are still unknown, and specific treatments are not yet available for them. Sometimes, chronic kidney disease may progress to kidney failure, requiring dialysis or kidney transplantation.
Treating high blood pressure with special medications called angiotensin converting enzyme ACE inhibitors often helps to slow the progression of chronic kidney disease. A great deal of research is being done to find more effective treatment for all conditions that can cause chronic kidney disease.
Kidney failure may be treated with hemodialysis, peritoneal dialysis or kidney transplantation. Treatment with hemodialysis the artificial kidney may be performed at a dialysis unit or at home.
Hemodialysis treatments are usually performed three times a week. Peritoneal dialysis is generally done daily at home. A kidney specialist can explain the different approaches and help individual patients make the best treatment choices for themselves and their families. Kidney transplants have high success rates. The kidney may come from someone who died or from a living donor who may be a relative, friend or possibly a stranger, who donates a kidney to anyone in need of a transplant.
Kidney disease usually affects both kidneys. If the kidneys' ability to filter the blood is seriously damaged by disease, wastes and excess fluid may build up in the body.
Although many forms of kidney disease do not produce symptoms until late in the course of the disease, there are six warning signs of kidney disease:. Skip to main content. How Your Kidneys Work. Why Are the Kidneys So Important? The kidneys are powerful chemical factories that perform the following functions: remove waste products from the body remove drugs from the body balance the body's fluids release hormones that regulate blood pressure produce an active form of vitamin D that promotes strong, healthy bones control the production of red blood cells Below you will find more information about the kidneys and the vital role they play in keeping your body functioning.
Where are the kidneys and how do they function? Kidney disease causes Kidney disease diagnosis Kidney disease treatment Kidney failure treatment What are the warning signs of kidney disease? How is your kidney health? Use our online curriculum to get individualized information for your stage of kidney disease. Enter Kidney Pathways.
Your kidneys also remove acid that is produced by the cells of your body and maintain a healthy balance of water, salts, and minerals—such as sodium , calcium , phosphorus , and potassium —in your blood. Watch a video about what the kidneys do. Each of your kidneys is made up of about a million filtering units called nephrons. Each nephron includes a filter, called the glomerulus , and a tubule. The nephrons work through a two-step process: the glomerulus filters your blood, and the tubule returns needed substances to your blood and removes wastes.
As blood flows into each nephron, it enters a cluster of tiny blood vessels—the glomerulus. The thin walls of the glomerulus allow smaller molecules, wastes, and fluid—mostly water—to pass into the tubule. Larger molecules, such as proteins and blood cells, stay in the blood vessel. A blood vessel runs alongside the tubule.
As the filtered fluid moves along the tubule, the blood vessel reabsorbs almost all of the water, along with minerals and nutrients your body needs. The tubule helps remove excess acid from the blood. The remaining fluid and wastes in the tubule become urine.
Blood flows into your kidney through the renal artery. This large blood vessel branches into smaller and smaller blood vessels until the blood reaches the nephrons. In the nephron, your blood is filtered by the tiny blood vessels of the glomeruli and then flows out of your kidney through the renal vein.
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