One of a pair of vertebrate organs the kidneys are situated in the body cavity near the spinal column and excrete waste products of metabolism. In humans they are bean-shaped organs about 4½ inches (11½ centimetres) long lying behind the peritoneum in a mass of fatty tissue, and consist chiefly of nephrons by which urine is secreted, collected, and discharged into the pelvis of the kidney when it is transported by the ureter to the bladder.
The kidneys are complicated organs that have numerous biological roles. Their primary role is to maintain the homeostatic balance of bodily fluids by filtering and secreting metabolites (such as urea) and minerals from the blood and excreting them, along with water, as urine. Because the kidneys are poised to sense plasma concentrations of ions such as sodium, potassium, hydrogen, oxygen, and compounds such as amino acids, creatinine, bicarbonate, and glucose, they are important regulators of blood pressure, glucose metabolism, and erythropoiesis (the process by which red blood cells (erythrocytes) are produced).
They are sensitive to the overall health of the body, the diet and body size, specific nutritional support may be helpful in maintaining optimal kidney function.
Each day, the kidneys filter approximately 200 quarts of blood, producing about 2 quarts of waste products and water. Filtered waste products include the normal organic material from the breakdown of cells, proteins, excess food by-products, and various minerals, as well as the individual waste excretions from cells of the body. Alcohol, drugs, excess protein, minerals, and ingested toxins are also filtered by the kidneys. These toxic agents can have a dramatic, destructive effect on the health and function of the kidneys.
The rate of blood flow through the kidneys is about 20% of the total blood pumped by the heart each minute.
References
- Teichert J, Tuemmers T, Achenbach H, Preiss C, Hermann R, Ruus P, Preiss R. Pharmacokinetics of alpha-lipoic acid in subjects with severe kidney damage and end-stage renal disease. J Clin Pharmacol. 2005 Mar;45(3):313-28. doi: 10.1177/0091270004270792. View Abstract.
- Teng M, Wolf M, Ofsthun MN, Lazarus JM, Hernan MA, Camargo CA Jr, Thadhani R. Activated injectable vitamin d and hemodialysis survival: a historical cohort study. J Am Soc Nephrol. 2005 Apr;16(4):1115-25. Epub 2005 Feb 23 View Abstract
- Matsumoto N, Riley S, Fraser D, et al. Butyrate modulates TGF-beta1 generation and function: potential renal benefit for Acacia(sen) SUPERGUM (gum arabic)? Kidney Int. 2006 Jan;69(2):257-65. View Abstract
- Kang KS, Kim HY, Yamabe N, et al. Protective Effect of Sun Ginseng against Diabetic Renal Damage. Biol Pharm Bull. 2006 Aug;29(8):1678-84. View Abstract
- Bosetti C, Scotti L, Maso LD, et al. Micronutrients and the risk of renal cell cancer: A case-control study from Italy. Int J Cancer. 2007 Feb 15;120(4):892-6. View Abstract
