Each kidney is about 4 or 5 inches long -- about the size of a fist. The kidneys' function are to filter the blood. All the blood in our bodies passes through the kidneys several times a day. The kidneys remove wastes, control the body's fluid balance, and regulate the balance of electrolytes.
Caffeine by Type of Brewed Coffee. Like all coffee drinks, caffeine levels vary greatly - due to variations in coffee blend, exact amount of ground coffee used, and brewing technique. The value of caffeine in brewed coffee featured above is an average, with values generally between 64 and 272 milligrams per cup. Because brewed coffee requires that the water is in contact with the grinds for a long time, this leads to a higher caffeine concentration (and sometimes an over-extracted taste).
Decaffeinated coffee has some caffeine, but the 2 to 4 mg in an 8-ounce cup is a smidgen compared with the caffeinated version. The lethal dose of caffeine is about 10 grams, which is equivalent to the amount of caffeine in 100 cups of coffee. Caffeine gets absorbed in the stomach and small intestine and then distributed throughout the body, including the brain.