In monogastric digestion, where does the majority of digestion and nutrient absorption occur?

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

Answer: (B)

In monogastric digestion, most digestion and nutrient absorption occur in the small intestine. Here, chyme mixes with pancreatic enzymes and bile to break down carbohydrates, proteins, and fats. The lining is folded into villi and microvilli, greatly increasing surface area so nutrients like glucose, amino acids, fatty acids, glycerol, vitamins, and minerals can be absorbed into the bloodstream efficiently. The stomach handles initial digestion with acid and pepsin and does some absorption, but not the bulk of nutrients. The cecum and large intestine primarily reclaim water and electrolytes and host microbial activity, producing some fermentation products, but nutrient absorption is far less extensive than in the small intestine.