ISSA Nutritionist Practice Exam

The small intestine is divided into three sections, which are?

1. Duodenum, jejunum, ileum

2. Jejunum, ileum, colon

3. Duodenum, ileum, cecum

4. Ileum, colon, rectum

The correct answer is: Duodenum, jejunum, ileum

The small intestine is indeed divided into three distinct sections: the duodenum, jejunum, and ileum. Each of these sections plays a specific role in the digestive process. The duodenum is the first part of the small intestine and is involved in the initial phase of digestion, where partially digested food from the stomach mixes with bile from the liver and digestive juices from the pancreas. This is crucial for breaking down fats, proteins, and carbohydrates. Following the duodenum, the jejunum is the middle section, which is primarily responsible for the absorption of nutrients. It has a highly vascularized structure to facilitate the efficient uptake of these nutrients into the bloodstream. The ileum, the final section, continues this process of absorption, particularly focusing on the absorption of vitamin B12 and bile salts, which are recycled back to the liver for reuse. Understanding the roles of these three sections of the small intestine is essential for comprehending the overall process of digestion and nutrient absorption. The other options provided incorrectly combine terms from different gastrointestinal system components, such as the colon and rectum, which are part of the large intestine, thus not representing the proper subdivisions of the small intestine.