Which is a sesamoid bone ?

Options

A. Patella
B. Femur
C. Ulna
D. Pterygoid

Answer

**Step-by-Step Solution:**

1. **Understanding Sesamoid Bones**: Sesamoid bones are small, round bones that are typically embedded within tendons. They help to protect tendons from stress and wear. The term "sesamoid" is derived from the Latin word "sesamum," which means sesame seed, indicating their small size.

2. **Identifying the Options**: The question provides four options:
- Patella
- Femur
- Ulna
- Pterygoid

3. **Analyzing Each Option**:
- **Patella**: This is the kneecap and is known to be the largest sesamoid bone in the human body. It is triangular in shape and protects the knee joint.
- **Femur**: This is the thigh bone and is the longest bone in the body. It is not a sesamoid bone.
- **Ulna**: This is one of the two bones in the forearm (the other being the radius). It is not a sesamoid bone.
- **Pterygoid**: This refers to pterygoid muscles and is associated with the skull. It is not a bone and therefore cannot be a sesamoid bone.

4. **Conclusion**: Based on the analysis, the correct answer is **Patella**, as it is the only option that is classified as a sesamoid bone.

**Final Answer**: The sesamoid bone is the **Patella**.

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