Female anatomy. Computer artwork of a female body showing her skeleton and urinary system. The kidneys can be seen (red), as well as the ureters, which lead to the bladder (lower centre), and the urethra (at bottom). The urinary system is responsible for fluid balance and waste excretion. Blood enters the kidneys where waste products are excreted to form a fluid called filtrate. Filtrate continues to collect additional waste products and minerals as it travels through the winding tubules of the kidney. Eventually, the filtrate becomes urine as it is channeled out of the kidney, into the ureters, down to the bladder (where it is stored) and eventually out through the urethra.