Select the incorrect statement w.r.t the structure of a bone

Options

A. The matrix of bone is present in the form of layers called lamellae
B. Lamellae consist of fluid filled spaces called lucanae
C. Lacunae contain bone cells called chondrocytes
D. The matrix is hard because of the presence of salts such as calcium phosphate

Answer

To solve the question of selecting the incorrect statement with respect to the structure of a bone, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Bone**:
- Bones are specialized connective tissues that provide support and structure to the body. They have a unique composition that includes a matrix, cells, and mineral deposits.

2. **Analyze the Statements**:
- **Statement 1**: "The matrix of bone is present in the form of layers called lamellae."
- This statement is **true**. The bone matrix is indeed organized into layers known as lamellae.

- **Statement 2**: "The lamellae consist of fluid-filled spaces called lacunae."
- This statement is also **true**. Lacunae are small spaces within the lamellae that contain bone cells.

- **Statement 3**: "The lacunae contain bone cells called chondrocytes."
- This statement is **false**. The lacunae contain bone cells known as **osteocytes**, not chondrocytes. Chondrocytes are the cells found in cartilage.

- **Statement 4**: "The matrix is hard because of the presence of salts such as calcium phosphate."
- This statement is **true**. The hardness of bone is primarily due to the presence of minerals like calcium phosphate and calcium carbonate.

3. **Identify the Incorrect Statement**:
- From the analysis, the incorrect statement is: "The lacunae contain bone cells called chondrocytes." This is incorrect because lacunae contain osteocytes.

4. **Conclusion**:
- The answer is option **C**: "Lacunae contain bone cells called chondrocytes."