Which is the longest section of the small intestine?

Which is the longest section of the small intestine?

• A. Jejunum
• B. Duodenum
• C. Ileum
• D. Cecum

Answer: (C)

The longest section of the small intestine is the ileum. The small intestine has three parts: a short first segment (duodenum) where chyme mixes with bile and pancreatic juices, a long middle portion (jejunum) where most nutrient absorption occurs, and a final portion (ileum) that extends longer than the others. In adults, the duodenum is about 25–30 cm, the jejunum roughly 2–2.5 meters, and the ileum about 3–4 meters, making the ileum the longest. The cecum is part of the large intestine, not the small intestine. The ileum also handles important absorption tasks like bile acids and vitamin B12, but its length mainly accounts for its role in extending absorption and transit before reaching the large intestine.

The longest section of the small intestine is the ileum. The small intestine has three parts: a short first segment (duodenum) where chyme mixes with bile and pancreatic juices, a long middle portion (jejunum) where most nutrient absorption occurs, and a final portion (ileum) that extends longer than the others. In adults, the duodenum is about 25–30 cm, the jejunum roughly 2–2.5 meters, and the ileum about 3–4 meters, making the ileum the longest. The cecum is part of the large intestine, not the small intestine. The ileum also handles important absorption tasks like bile acids and vitamin B12, but its length mainly accounts for its role in extending absorption and transit before reaching the large intestine.