Where does most digestion take place in the human digestive system?

• A. Small intestine
• B. Stomach
• C. Large intestine
• D. Esophagus

Answer: (A)

Verified step by step guidance

1. Step 1: Begin by understanding the primary function of each organ listed in the options. The stomach is responsible for mechanical digestion and the initial breakdown of proteins using gastric juices. The esophagus is a muscular tube that transports food from the mouth to the stomach but does not perform digestion. The large intestine primarily absorbs water and electrolytes, with minimal digestion occurring.
2. Step 2: Focus on the small intestine. It is the longest part of the digestive system and is specialized for most digestion and nutrient absorption. Enzymes from the pancreas and bile from the liver are secreted into the small intestine to aid in breaking down carbohydrates, proteins, and fats.
3. Step 3: Recall that the small intestine has three sections: the duodenum, jejunum, and ileum. The duodenum is where most chemical digestion occurs, while the jejunum and ileum are primarily involved in nutrient absorption.
4. Step 4: Compare the functions of the small intestine with the other organs listed. The small intestine is the only organ where most digestion and absorption of nutrients occur, making it the correct answer.
5. Step 5: Conclude that the correct answer is 'Small intestine' based on its role in digestion and nutrient absorption, supported by the anatomical and physiological functions of the digestive system.