Texas Medical Assistant Certification Practice Test

What lines the inside of the bone?

1. Osteoclasts

2. Endosteum

3. Diaphysis

4. Periosteum

The correct answer is: Endosteum

The endosteum is the correct choice because it specifically refers to the thin, delicate membrane that lines the inner surface of bones, including the cavities within the bone, such as the medullary cavity. This membrane is crucial because it contains osteoblasts, which are the cells responsible for bone formation, and it helps in the process of bone remodeling and repair. In contrast, osteoclasts are cells that break down bone tissue but are not a lining. The diaphysis refers to the shaft of a long bone and is not an inner lining. The periosteum is a dense layer of vascular connective tissue enveloping the bones, but it covers the outer surface rather than lining the inside. Therefore, the endosteum is the specialized lining pertinent to the interior of the bone structure, making it the correct answer.