Outermost layer of bone, inner lining of bone marrow cavity are lined respectively by 

Options

A. endosteum, periosteum
B. Periosteum, endosteum
C. Perichondrium & endosteum
D. periosteum, endochondrium

Answer

To answer the question about the outermost layer of bone and the inner lining of the bone marrow cavity, we need to identify the correct terms for these structures.

### Step-by-Step Solution:

1. **Understanding Bone Structure**:
- Bones have various layers and linings. The outermost layer is crucial for protection and attachment of muscles, while the inner lining is important for the bone marrow, which is involved in blood cell production.

2. **Identifying the Outermost Layer**:
- The outermost layer of bone is known as the **periosteum**. This is a dense layer of vascular connective tissue that envelops the bones except at the surfaces of the joints.

3. **Identifying the Inner Lining of the Bone Marrow Cavity**:
- The inner lining of the bone marrow cavity is called the **endosteum**. This is a thin layer of connective tissue that lines the inner surface of the bone, including the medullary cavity.

4. **Matching the Terms to Options**:
- Now, we need to match these terms to the options provided in the question. The correct pairing is:
- Outermost layer of bone: **Periosteum**
- Inner lining of bone marrow cavity: **Endosteum**

5. **Conclusion**:
- Therefore, the correct answer to the question is that the outermost layer of bone and the inner lining of the bone marrow cavity are lined respectively by **periosteum and endosteum**.

### Final Answer:
**Periosteum and Endosteum**

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