Which of the following is not correct about acetabulum ?

Options

A. It is a part of pectoral girdle.
B. It articulates with the head of femur to form the hip joint.
C. It is formed by the fusion of ilium, ischium and pubis.
D. It is a part of pelvic girdle.

Answer

To determine which statement about the acetabulum is incorrect, let's analyze each option step by step.

### Step 1: Understanding the Acetabulum
The acetabulum is a cup-shaped socket in the pelvis that articulates with the head of the femur (thigh bone) to form the hip joint. It is crucial to know where the acetabulum is located and its function.

### Step 2: Evaluating Option A
**Statement A: It is part of the pectoral girdle.**
- The pectoral girdle consists of the clavicles and scapulae, which support the upper limbs. The acetabulum is not part of this structure. Therefore, this statement is incorrect.

### Step 3: Evaluating Option B
**Statement B: It articulates with the head of femur to form the hip joint.**
- This statement is true. The acetabulum does indeed articulate with the head of the femur, forming the hip joint.

### Step 4: Evaluating Option C
**Statement C: It is formed by fusion of ilium, ischium, and pubis.**
- This statement is also true. The acetabulum is formed at the point where the ilium, ischium, and pubis bones fuse together in the pelvic girdle.

### Step 5: Evaluating Option D
**Statement D: It is part of the pelvic girdle.**
- This statement is true. The acetabulum is a key component of the pelvic girdle.

### Conclusion
After evaluating all the statements, the incorrect statement about the acetabulum is:
**A. It is part of the pectoral girdle.**

### Summary of Steps:
1. Understand the function and location of the acetabulum.
2. Evaluate each statement regarding the acetabulum.
3. Identify the incorrect statement.