Which of the following is the longest portion of small intestine?
(a) Duodenum
(b) Ileum
(c) Caecum
(d) Jejunum

Options

A. Duodenum
B. Ileum
C. Caecum
D. Jejunum

Answer

To determine which portion of the small intestine is the longest, we need to analyze the three segments of the small intestine: the duodenum, jejunum, and ileum.

1. **Identify the segments of the small intestine**:
- The small intestine is divided into three main parts:
- **Duodenum**: This is the first segment.
- **Jejunum**: This is the second segment.
- **Ileum**: This is the third and final segment.

2. **Understand the characteristics of each segment**:
- **Duodenum**: This is the shortest segment of the small intestine. It primarily receives partially digested food from the stomach.
- **Jejunum**: This segment is the middle part of the small intestine and is involved in the absorption of nutrients.
- **Ileum**: This is the longest segment of the small intestine. It is responsible for the absorption of nutrients and the remaining material is passed into the large intestine.

3. **Compare the lengths of each segment**:
- Based on the definitions:
- Duodenum is the shortest.
- Jejunum is longer than the duodenum but shorter than the ileum.
- Ileum is the longest segment of the small intestine.

4. **Conclusion**:
- Therefore, the longest portion of the small intestine is the **ileum**.

The correct answer is **(b) Ileum**.

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