Which type of joint has a fluid filled cavity for significant role in locomotion ?

Options

A. Fibrous joints
B. Cartilagenous joints
C. Synovial joints
D. All the above

Answer

**Step-by-Step Solution:**

1. **Understanding Joints**: A joint is defined as a point of contact between two bones or between bones and cartilages. This definition helps us identify the different types of joints based on their structure and function.

2. **Types of Joints**: The main types of joints include:
- Fibrous joints: These joints are connected by dense connective tissue and do not have a fluid-filled cavity.
- Cartilaginous joints: These joints are connected by cartilage and also do not have a fluid-filled cavity.
- Synovial joints: These joints have a fluid-filled cavity, which is crucial for movement.

3. **Identifying the Fluid-Filled Cavity**: Among the types of joints, synovial joints are characterized by the presence of a synovial cavity filled with synovial fluid. This fluid serves several important functions, including lubrication, reducing friction, and providing nutrients to the cartilage.

4. **Role in Locomotion**: The synovial fluid and cavity play a significant role in locomotion by allowing for smooth and flexible movement between the articulating surfaces of the bones. This is essential for activities such as walking, running, and jumping.

5. **Example of Synovial Joint**: A common example of a synovial joint is the knee joint, which allows for a wide range of motion and is crucial for locomotion.

6. **Conclusion**: Based on the characteristics and functions discussed, the type of joint that has a fluid-filled cavity and plays a significant role in locomotion is the **synovial joint**.

**Final Answer**: Synovial joints.

---