What is the principal function of the excretory structure bladder?

The principal function of the bladder is to store urine produced by the kidneys until it is ready to be excreted from the body. It acts as a temporary reservoir that allows for the controlled release of urine during urination. The bladder's muscular walls contract to expel urine through the urethra when the body signals the need to void. This function is crucial for maintaining fluid balance and eliminating waste products from the body.