Which structures make up the urinary system?

The urinary system is primarily responsible for the production, storage, and excretion of urine, which helps regulate water and electrolyte balance in the body. The correct answer, comprising the kidneys, ureters, bladder, and urethra, represents the main structural components of this system.

The kidneys are the pivotal organs that filter blood to produce urine, removing waste products and excess substances. Once urine is formed, it travels through the ureters, which are muscular tubes that transport urine from each kidney to the bladder. The bladder serves as a storage reservoir for urine until it is expelled from the body. Lastly, the urethra is the duct through which urine is released during urination.

In contrast, other choices include structures that do not belong to the urinary system. The gallbladder and liver are integral to the digestive system, functioning in bile storage and production, respectively. The rectum is part of the gastrointestinal tract and is not involved in urinary functions but rather in the excretion of solid waste. Therefore, the collection of the kidneys, ureters, bladder, and urethra is the accurate representation of the urinary system's anatomy.