Set of coiled structures of the following is

Options

A. Oral cavity and pharynx
B. Jejunum and ileum
C. Stomach and duodenum
D. Duodenum and jejunum

Answer

To solve the question regarding the set of coiled structures, we will analyze the options provided step by step.

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for a set of coiled structures in the digestive system. We need to identify which options consist of coiled structures.

2. **Evaluate the First Option: Oral Cavity and Pharynx**:
- **Oral Cavity**: This is the mouth area where the tongue and teeth are located. It is not a coiled structure; it is relatively flat and open.
- **Pharynx**: This is the part of the throat behind the mouth and nasal cavity. It serves as a pathway for food and air but is also not coiled.
- **Conclusion**: This option does not consist of coiled structures.

3. **Evaluate the Second Option: Jejunum and Ileum**:
- **Jejunum**: This is the second part of the small intestine and is known to be coiled.
- **Ileum**: This is the third part of the small intestine, following the jejunum, and is also coiled.
- **Conclusion**: Both jejunum and ileum are coiled structures, making this option valid.

4. **Evaluate the Third Option: Stomach and Duodenum**:
- **Stomach**: This is a sac-like structure that stores food and is not coiled.
- **Duodenum**: This is the first part of the small intestine where the stomach empties its contents. While it does have a curved shape, it is not considered a coiled structure.
- **Conclusion**: This option does not consist of coiled structures.

5. **Evaluate the Fourth Option: Duodenum and Duodenum**:
- This option is likely a repetition and does not provide a valid pair for consideration. The duodenum itself is not a coiled structure.
- **Conclusion**: This option does not consist of coiled structures.

### Final Answer:
The set of coiled structures is **Jejunum and Ileum**.

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