Kidneys are bean-shaped

Most people have two kidneys. They are bean-shaped organs located on both sides of the spine, behind the stomach. Each one is about the size of an adult fist. Their main purpose is to keep the composition of blood in the body balanced to maintain good health. 

Function

The kidneys filter extra water and toxins from the blood. The kidneys filter about 120 to 152 quarts (113 to 144 liters) of blood to create 1 to 2 quarts (0.94 to 1.8 l) of urine every day, according to the National Institutes of Health (NIH). 

They aren’t just one big filtering sponge, though. Each kidney is a system of millions of tiny filters called nephrons. A nephron has two parts. The glomerulus is the first part of the filter. It strains blood cells and large molecules from the toxins and fluid. The fluids and toxins that pass through then go through the tubule. The tubule collects minerals that the body needs and puts them back into the bloodstream and filters                                                       out more toxins                                                                                                                                          

Life After Brain Death: Is the Body Still 'Alive'?

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A 13-year-old girl in California continues to be on a ventilator after being declared brain-dead by doctors. Although a brain-dead person is not legally alive, how much of the body will keep on working with the help of technology, and for how long?

Jahi McMath of Oakland, Calif., was declared brain-dead last month after experiencing an extremely rare complication from tonsil surgery. Jahi's family members have fought to keep their daughter on a ventilator, but a judge has ordered that the machine be turned off next week.

A person is considered brain-dead when he or she no longer has any neurological activity in the brain or brain stem — meaning no electrical impulses are being sent between brain cells. Doctors perform a number of tests to determine whether someone is brain-dead, one of which checks whether the individual can initiate his or her own breath, a very primitive reflex carried out by the brain stem, said Dr. Diana Greene-Chandos, an assistant professor of neurological surgery and neurology at Ohio State University Wexner Medical Center. "It's the last thing to go," Greene-Chandos said. [10 Surprising Facts About the Brain]