HOSA Foundations of Nutrition Practice Test

The duodenum is the first section of the small intestine. It sits right after the stomach and receives chyme along with digestive juices from the pancreas and bile from the liver. This is where chemical digestion ramps up: bicarbonate from the pancreas neutralizes stomach acid, enzymes break down fats, proteins, and carbohydrates, and the chyme mixes with bile and pancreatic juice to begin nutrient breakdown. While absorption starts here, the bulk of nutrient uptake happens later in the jejunum and ileum. The jejunum is the middle section where most absorption occurs, the ileum continues absorption and bile acid reabsorption, and the cecum is the pouch at the start of the large intestine, not part of the small intestine.