Author: Dr Brent Yanke Urologist West Orange New Jersey 2008-07-28
Hematuria: Blood in the Urine
KIDNEY ANATOMY AND FUNCTION
The
kidneys are organs responsible for cleansing the blood of waste. Many
byproducts of metabolic processes in the body build up in the
bloodstream. A microscopic tubular system within the kidney filters the
blood and removes these byproducts before they can accumulate to
dangerous levels. Once blood enters the kidney, it is transported to a
collection of small capillary vessels, called the glomerulus. As the
blood passes through the glomerulus, the filtrated waste shifts to
Bowman’s capsule, a pouch that surrounds the glomerulus and starts the
tubular system. Kidney tissue is separated into two layers: the outer
cortex and the inner medulla. Once the filtered waste passes through
these layers, it reaches the renal papillae which project into the renal
pelvis, an open space in the core of the kidney, where the urine
collects. The urine then drains from the renal pelvis into the ureter
and finally into the bladder. The kidneys and ureters comprise the upper
urinary tract, while the bladder and urethra comprise the lower urinary
tract (Figure 1).