Which set correctly lists the three main functions of the digestive system?

• A. Ventilation, gas exchange, and transport of respiratory gases
• B. Filtration, reabsorption, and secretion
• C. Hormone production, impulse conduction, and muscle contraction
• D. Digestion, absorption, and elimination

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the primary role of the digestive system, which is to process food and extract nutrients necessary for the body's energy and growth.
2. Step 2: Identify the three main functions of the digestive system: digestion (breaking down food into smaller molecules), absorption (transporting nutrients into the bloodstream), and elimination (removing indigestible substances as waste).
3. Step 3: Compare the given options with these functions to see which set matches the digestive system's roles.
4. Step 4: Recognize that options like ventilation and gas exchange relate to the respiratory system, filtration and reabsorption relate to the urinary system, and hormone production and impulse conduction relate to the endocrine and nervous systems respectively.
5. Step 5: Conclude that the correct set listing the three main functions of the digestive system is digestion, absorption, and elimination.