The Kidney & its Functions

Most people feel the kidney is just another body organ. Few actually know or have read about how vital they really are and the numerous functions they play a role in. A general overview of these vital bean shaped organs and their functions will help better understand the importance of these organs and their primary role in maintaining 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 thus eliminating impurities in the human body. 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). In medical terminology kidneys and diseases of the kidney is called nephrology. There are two, one on each side of the spine; the right kidney sits just below the diaphragm and posterior to the liver, the left below the diaphragm and posterior to the spleen. The kidneys are about 9 to 13 cm in diameter, the left being slightly larger that the right. The kidneys receive unfiltered blood directly from the heart through the abdominal aorta which then branches to the left and right renal arteries. Filtered blood then returns by the left and right renal veins to the inferior vena cava and then the heart. Renal blood flow accounts for up to a third of the cardiac output. The kidneys excrete a variety of waste products produced by metabolism, including the nitrogenous wastes: urea (from protein catabolism) and uric acid (from nucleic acid metabolism) and water