What is the function of the bladder in the urinary system?

The primary function of the bladder in the urinary system is to store urine until it is ready to be expelled from the body. The bladder is a muscular, expandable organ that collects urine produced by the kidneys. As it fills, stretch receptors signal the central nervous system, which generates the urge to urinate when the bladder reaches a certain capacity. When instructed to do so, the bladder muscles contract, facilitating the expulsion of urine through the urethra.

This storage function is critical because it allows the body to maintain continence and control over urination, ensuring that waste is removed efficiently and at appropriate times. The bladder plays a vital role in the overall regulation of fluid balance and waste excretion in the body. Other functions mentioned in the choices, such as filtering blood, producing urine, and regulating blood pressure, are related to other components of the urinary system, specifically the kidneys, and do not pertain to the bladder's role.