Kevin Flores ANATVO1 December 4, 2008 Kidneys Each bean-shaped kidney measures about four to five inches long, about the size of an adult fist. Yet in spite of their diminutive size, your kidneys are biological powerhouses. Although they constitute less than 1% of your body weight, at any given time they receive about 20% of your blood. Your kidneys are busy monitoring, cleansing, and recycling about 50 gallons of blood every 24 hours. That means all 10 pints of blood in the average person’s body are processed about 40 times a day. The wastes in from blood come from the normal breakdown of active tissues and from the food you eat. The body takes energy from the food and for self-repairs. After your body has taken what it needs from the food, waste is sent to the blood. If your kidneys did not remove these wastes, the wastes would build up in the blood and damage the body. The actual filtering occurs in tiny units inside your kidneys called nephrons. Every 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. A complicated chemical exchange takes place, as waste materials and water leave your blood and enter your urinary system. At first, the tubules receive a combination of waste materials and chemicals that your body can still use. Your kidneys measure out chemicals like sodium, phosphorus, and potassium and release them back to the blood to return to the body. In this way, the kidneys regulate the body’s level of these substances. The right balance is necessary for life, but excess levels can be harmful. Unfortunately, kidney diseases cannot be cured but there are certain ways to avoid it. Avoid illegal drugs and the overuse of prescription and over-the-counter drugs, control blood pressure; reduce high blood pressure, avoid a high sodium diet, know your family health history, and most of all quit smoking. Have your urine checked...