How Much of the HumanBody Is Replaceable?

     

    Fans of the old TV shows and saw scientists revive nearly dead human beings, bringing them back to life with high-tech body parts that gave them extraordinary capabilities. Today, replacing parts of the human body using state-of-the-art technology is moving out of the realm of science fiction and into reality.

       

  Replacement of body parts means transplanting organs and tissues from one person to another or using artificial body parts. Organs currently transplanted are the heart, kidneys, liver, lungs, pancreas, and intestines. Tissues and cells include the corneas, cartilage, muscles, tendons, ligaments, skin, and heart valves (mechanical versions of the valves are also used).

     

  Artificial limbs and organs can replace parts throughout the body. Doctors commonly replace knees and hips, along with finger, elbow, and shoulder joints. Cochlear implants are electronic devices that restore hearing, and researchers are currently testing a new brain implant that can help patients who lack functioning auditory nerves. Prosthetic noses, hands,  arms, and legs are available; artificial legs
are among the most sophisticated prosthetics today, and researchers continue to improve “bionic” hands with an almost human sense of touch. One, the bebionic3, has 14 different grip patterns, including  ones that allow users to pick up a coin or write with a pen.

      

  The science of developing artificial body parts is constantly changing. In 2014, hospitals across the United States tested a “bioartificial” liver that combines liver cells and a mechanical device that together perform liver functions outside the body while a patient’s diseased liver regenerates healthy tissue. Researchers in Japan and elsewhere are developing 3-D printers that combine stem cells and artificial materials to custom-make artificial ears. The Japanese team hopes to also create skin and bones using this method.

     

  Scientists are also working to grow real replacement parts in the lab. Doris Taylor of the Texas Heart Institute is one of the pioneers in using stem cells to create such body parts as hearts, livers, and kidneys for transplants. Taylor says, “I absolutely see a day where you’ll walk into a manufacturing facility somewhere, and there will be jars of kidneys, jars of livers, and jars of lungs, whatever it is you need.”