described the urinary system’s basic structure and
function in his writings. However, nearly 2000
years would pass before one of science’s most sig-
nificant inventions, the light microscope, would
give 17th-century scientists the opportunity to
explore the amazing structure and function of the
kidney beyond the human EYE’s ability to detect.
Advances in modern times such as the electron
microscope, which debuted in the 1950s, and the
mapping of the human GENOME, completed in 2003
after 13 years of research, extended to the molecu-
lar level understanding of the seemingly simple yet
incredibly intricate mechanisms that filter the
blood and cleanse the body of metabolic wastes.
Breakthrough Research and Treatment AdvancesThe first successful KIDNEY TRANSPLANTATION in
1954, in which surgeons removed one healthy
kidney from a man and transplanted it into his
identical twin brother whose kidneys had com-
pletely failed, marked the advent of a new era in
modern medicine. The discovery of cyclosporine, a
powerful immunosuppressive DRUG, in 1954, made
kidney transplantation a viable treatment for
ESRD and paved the way for the transplantation
of other vital organs such as livers and hearts.
Today, surgeons in the United States perform
more than 15,000 kidney transplantations each
year, making the kidney the most frequently
transplanted organ (aside from SKINand corneas).
Yet 45,000 people wait for donor kidneys. The
shortage of donor kidneys has spurred efforts to
find new solutions. One direction of research
focuses on living kidney donation, in which a per-
son agrees to provide one of his or her kidneys to
a person whose own kidneys have failed.
Advances in MINIMALLY INVASIVE SURGERYhave sig-
nificantly reduced the risks and inconveniences
for living donors. Other directions of research
focus on molecular medicine and genetics, looking
for ways to correct problems with the kidneys to
prevent kidney failure.174 The Urinary System