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

The bladder's primary function is to store urine produced by the kidneys before it is excreted from the body. This muscular sac can expand as it fills with urine, allowing for significant storage capacity. When the bladder reaches a certain volume, nerve signals prompt the sensation of urgency and the need to urinate, leading to the voluntary contraction of the bladder muscles. This mechanism plays a crucial role in regulating fluid balance and waste elimination in the body.

Other functions mentioned in the options, such as filtering blood, absorbing nutrients, and producing hormones, are carried out by different organs within the urinary or related systems. The kidneys, for instance, filter blood to create urine, while nutrient absorption occurs in the intestines, and hormone production is a primary function of various glands throughout the body.