The joint in which one of the two bones is fixed in its place and bears a peg like process over which the other bone rotates is called

Options

A. hinge joint
B. saddle joint
C. pivot joint
D. angular joint

Explanation

To answer the question, "The joint in which one of the two bones is fixed in its place and bears a peg-like process over which the other bone rotates is called," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Joint Structure**:
- We need to identify a joint where one bone is fixed and the other rotates around it. This is a key characteristic of a specific type of joint.

2. **Identifying the Type of Joint**:
- The joint described is known as a **pivot joint**. In a pivot joint, one bone has a peg-like structure that fits into a ring formed by another bone, allowing for rotational movement.

3. **Examples of Pivot Joints**:
- A classic example of a pivot joint is found between the **atlas (C1)** and **axis (C2)** vertebrae in the neck. The atlas holds the skull and allows for the rotation of the head, while the axis provides the peg-like structure around which the atlas rotates.

4. **Differentiating from Other Joints**:
- Other types of joints such as hinge joints (like the knee), saddle joints (like the thumb), and angular joints (like the wrist) do not fit the description provided in the question. Hinge joints allow movement in one plane, saddle joints allow movement in multiple directions, and angular joints allow movement in two directions.

5. **Conclusion**:
- Therefore, the correct answer to the question is that the joint described is a **pivot joint**.

### Final Answer:
The joint in which one of the two bones is fixed in its place and bears a peg-like process over which the other bone rotates is called a **pivot joint**.

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