The excretory system, is composed of multiple
organs. The primary organ is the kidney. The kidney performs the dual tasks of
filtering out wastes and purifying blood. Other organs in the excretory system
include; the urinary bladder, the ureters, and the urethra. The urinary bladder is a large
hollow muscular sac that holds urine. The ureters are two tubes that transport urine
from the kidneys to the urinary bladder. The urethra is a tube that transports urine
from the bladder to an opening outside the body.