University of Central Florida (UCF) ZOO3733C Human Anatomy Practice Test 4

The correct answer is the second or descending part of the duodenum, as it is in this section that the major and minor duodenal papillae are located. The major duodenal papilla is the site where the bile and pancreatic ducts empty their secretions into the duodenum. This is significant because it plays a crucial role in digestion, allowing essential enzymes and bile to enter the small intestine to aid in the breakdown of food.

The minor duodenal papilla is located slightly above the major one and is associated with the accessory pancreatic duct. Although its function may not be as prominent as that of the major papilla, it still contributes to the regulation of digestive fluid entry.

In contrast, the first (or ascending) part of the duodenum primarily acts as the initial section receiving chyme from the stomach, but does not contain these papillae. The third (horizontal) part primarily serves as a conduit, and the fourth (ascending) part connects to the jejunum without the presence of the papillae. Hence, the second or descending part of the duodenum is uniquely responsible for the major and minor duodenal papillae, making it the correct choice.