Through which two systems is carbon dioxide primarily eliminated from the human body?

• A. Digestive and integumentary systems
• B. Respiratory and circulatory systems
• C. Respiratory and digestive systems
• D. Respiratory and urinary systems

Answer: (D)

Verified step by step guidance

1. Step 1: Begin by understanding the role of carbon dioxide (CO₂) in the human body. CO₂ is a waste product of cellular respiration, which occurs in cells during energy production.
2. Step 2: Recognize that CO₂ must be eliminated from the body to maintain homeostasis and prevent toxic buildup. This elimination primarily involves systems responsible for gas exchange and waste removal.
3. Step 3: Examine the respiratory system's role. The lungs are the primary organs where CO₂ is exchanged for oxygen during breathing. CO₂ diffuses from the blood into the alveoli and is expelled during exhalation.
4. Step 4: Consider the urinary system's role. While the urinary system primarily eliminates nitrogenous wastes, it does not play a significant role in CO₂ removal. Instead, focus on the circulatory system, which transports CO₂ from tissues to the lungs for elimination.
5. Step 5: Conclude that the two systems primarily responsible for CO₂ elimination are the respiratory system (via exhalation) and the circulatory system (via transport of CO₂ in the blood to the lungs).