Which of the following is not a sesamoid bone?

Options

A. Radius
B. Patella
C. Fibula
D. Pisciform

Answer

To determine which of the following is not a sesamoid bone, we need to understand what a sesamoid bone is and identify the options provided.

### Step-by-Step Solution:

1. **Definition of Sesamoid Bones**:
- Sesamoid bones are small, rounded bones that develop within tendons or joint capsules. They help in reducing friction and improving the mechanical advantage of muscles.

2. **Characteristics of Sesamoid Bones**:
- They are typically small and rounded in shape.
- They are found in locations where tendons pass over joints.

3. **Examples of Sesamoid Bones**:
- Common examples include:
- **Patella** (kneecap)
- **Pisiform** (a wrist bone)
- **Incus** (one of the ear ossicles)

4. **Identifying the Options**:
- The options provided are:
- **1. Radius**
- **2. Patella**
- **3. Fibula**
- Now, we need to analyze each option to determine if it is a sesamoid bone or not.

5. **Analysis of Each Option**:
- **Patella**: This is a well-known sesamoid bone located in the knee.
- **Fibula**: This is a long bone located in the lower leg, not a sesamoid bone.
- **Radius**: This is also a long bone in the forearm, not a sesamoid bone.

6. **Conclusion**:
- Among the options, the **Radius** is not a sesamoid bone. Therefore, the correct answer is **Option 1: Radius**.