What is the primary function of the urethra?

The primary function of the urethra is to expel urine from the bladder. The urethra serves as the final pathway through which urine exits the body after it has been collected in the urinary bladder. During urination, the bladder contracts, and the urethra opens to allow the passage of urine out of the body. This process is essential for the regulation of urine elimination and maintaining homeostasis.

While the other options include processes such as transporting blood to the kidneys, filtering waste from blood, and producing hormones, these functions are associated with different parts of the urinary system. For example, the kidneys are responsible for filtering blood and producing urine, while the bladder serves as a storage site for urine until it is expelled. The urethra is specifically designed for the final stage of this process, highlighting its critical role in urinary function.