What are the primary waste products that the urinary system excretes?

• A. Urea, creatinine, and excess ions
• B. Carbon dioxide and glucose
• C. Hormones and enzymes
• D. Vitamins and minerals

Answer: (A)

The urinary system is primarily responsible for filtering blood and excreting waste products that result from metabolic processes in the body. Urea, creatinine, and excess ions are the primary waste products excreted.

Urea is formed from the breakdown of proteins during metabolic processes and is a major component of urine. Creatinine is a byproduct of muscle metabolism, specifically from the breakdown of creatine, and it is also excreted by the kidneys in the urine. Excess ions, such as sodium, potassium, and chloride, are regulated by the kidneys to maintain electrolyte balance and are excreted in response to changes in dietary intake or bodily needs.

The other options mention substances that are not primarily excreted by the urinary system. Carbon dioxide is primarily a waste product expelled by the respiratory system, not the urinary system. Hormones and enzymes are not waste products; rather, they are important biochemical substances produced by various glands and organs. Lastly, vitamins and minerals are nutrients that the body requires but are not classified as waste products excreted specifically by the urinary system. Therefore, the focus on urea, creatinine, and excess ions accurately reflects the primary role of the urinary system in waste excretion.