Which anatomical structure is responsible for producing urine?

The kidneys are the primary anatomical structures responsible for producing urine. They serve a crucial role in the urinary system by filtering blood, removing waste products, and regulating water and electrolyte balance. Each kidney contains approximately one million tiny units called nephrons, where the filtration of blood occurs. Within the nephrons, waste and excess substances are reabsorbed, secreted, or excreted to form urine, which then passes through the ureters to the bladder for storage before being expelled from the body.

The other options have different functions within the urinary system. The urethra is the tube that conducts urine from the bladder to the outside of the body, the bladder is responsible for storing urine until it is ready to be expelled, and the prostate is a gland that produces seminal fluid and plays a role in male reproductive functions, but it does not produce urine.