Final answer:
The small intestine is responsible for the absorption of nutrients, including carbohydrates, proteins, water, and lipids. Most absorption of carbohydrates and proteins occurs in the jejunum, while bile salts and vitamin B12 are absorbed in the terminal ileum.
Step-by-step explanation:
Almost all ingested food, 80 percent of electrolytes, and 90 percent of water are absorbed in the small intestine. Although the entire small intestine is involved in the absorption of water and lipids, most absorption of carbohydrates and proteins occurs in the jejunum. Notably, bile salts and vitamin B12 are absorbed in the terminal ileum.