Which substances does the urinary system primarily excrete to eliminate waste from the body?

• A. Urea and creatinine
• B. Glucose and amino acids
• C. Bile and bilirubin
• D. Carbon dioxide and oxygen

Answer: (A)

Verified step by step guidance

1. Understand the primary function of the urinary system, which is to filter blood and remove waste products from the body.
2. Identify the main waste products that are excreted by the urinary system. These are typically nitrogenous wastes resulting from protein metabolism.
3. Recognize that urea is a major nitrogenous waste product formed in the liver from ammonia, which is then transported to the kidneys for excretion.
4. Understand that creatinine is another waste product, formed from the breakdown of creatine phosphate in muscle, and is excreted by the kidneys.
5. Note that glucose and amino acids are typically reabsorbed by the kidneys and not excreted as waste, while bile and bilirubin are processed by the liver and excreted via the digestive system, and carbon dioxide is expelled by the respiratory system.