Most chemical digestion and nutrient absorption occurs in which part of the small intestine?

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Multiple Choice

Most chemical digestion and nutrient absorption occurs in which part of the small intestine?

Jejunum. After chyme mixes with bile and pancreatic juice in the duodenum to begin digestion, the next section of the small intestine provides the most extensive site for nutrient absorption. The jejunum has a huge surface area thanks to long, finger-like villi and microscopic microvilli, plus a rich supply of enterocytes with transporters that rapidly bring glucose, amino acids, and fatty acids into the body. Lipids are absorbed as fatty acids and monoglycerides and taken up into the lymphatic system, while other nutrients enter the blood. The ileum handles bile acid and vitamin B12 reabsorption, and the cecum is part of the large intestine, so they don’t contribute as much to overall nutrient absorption as the jejunum.

Jejunum. After chyme mixes with bile and pancreatic juice in the duodenum to begin digestion, the next section of the small intestine provides the most extensive site for nutrient absorption. The jejunum has a huge surface area thanks to long, finger-like villi and microscopic microvilli, plus a rich supply of enterocytes with transporters that rapidly bring glucose, amino acids, and fatty acids into the body. Lipids are absorbed as fatty acids and monoglycerides and taken up into the lymphatic system, while other nutrients enter the blood. The ileum handles bile acid and vitamin B12 reabsorption, and the cecum is part of the large intestine, so they don’t contribute as much to overall nutrient absorption as the jejunum.

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