From the Research
The duodenum and jejunum are distinct segments of the small intestine with several key differences, primarily in their structure, function, and location, as noted in various studies 1, 2, 3, 4, 5. The duodenum is the first and shortest section (about 10-12 inches long), beginning at the pylorus of the stomach and forming a C-shape around the head of the pancreas. It receives digestive secretions from the pancreas and liver through the pancreatic and bile ducts. The duodenum has a thicker wall, more Brunner's glands that secrete alkaline mucus to neutralize stomach acid, and contains more circular folds called plicae circulares. In contrast, the jejunum is the middle segment of the small intestine (about 8 feet long), connecting the duodenum to the ileum. It has a larger diameter but thinner walls than the duodenum, appears redder due to greater vascularity, and contains fewer Brunner's glands but more goblet cells. The jejunum has more pronounced plicae circulares and villi, making it specialized for nutrient absorption, particularly carbohydrates and proteins. While the duodenum focuses on neutralizing stomach acid and beginning digestion, the jejunum primarily functions in nutrient absorption. Some studies have investigated the treatment of duodenal ulcers, including the use of proton pump inhibitors (PPIs) 2, 3, 5, but these do not directly inform the anatomical and functional differences between the duodenum and jejunum. Key differences between the duodenum and jejunum include:
- Location and length
- Wall thickness and composition
- Presence of Brunner's glands and goblet cells
- Specialization for digestion versus nutrient absorption The most recent and highest quality study does not directly address the differences between the duodenum and jejunum, but based on general medical knowledge, the duodenum and jejunum have distinct characteristics that are essential for their respective functions in the digestive system.