Which of the following is the FIRST section of the small intestine?

The first section of the small intestine is the duodenum. It plays a crucial role in digestion by receiving partially digested food from the stomach, along with bile from the liver and pancreatic juice from the pancreas. The duodenum is responsible for the initial breakdown of food using these digestive juices, which helps to neutralize stomach acid and further digest nutrients.

Understanding the structure and function of the duodenum helps to clarify its importance in the digestive process, setting the stage for the subsequent absorption of nutrients that occurs in the jejunum and ileum, the other sections of the small intestine. The identification of the duodenum as the initial region emphasizes its unique role in digestion compared to other parts of the intestine or sections that do not belong to the small intestine, like the cecum, which is part of the large intestine.