Question

1. moving from deep to superficial, the layers covering bone marrow are:

a. spongy bone, compact bone, periosteum
b. sponay bone, periosteum, compact bone
c. periosteum, spongy bone, compact bone
d. compact bone, spongy bone, periosteum

Explanation:

To determine the layers covering bone marrow from deep to superficial, we recall the structure of bone:

• Bone marrow is located within the spaces of spongy (cancellous) bone.
• Surrounding the spongy bone is compact (cortical) bone, which provides strength.
• The outermost layer of a bone (except at joints, which have articular cartilage) is the periosteum, a dense connective tissue layer.

So from deep (closest to marrow) to superficial (outermost), the order is spongy bone (where marrow resides), then compact bone, then periosteum.

Let's analyze the options:

• Option a: Spongy bone (deep, around marrow), compact bone (middle), periosteum (superficial, outer) → matches the correct order.
• Option b: Incorrect order (periosteum is outer, not between spongy and compact).
• Option c: Incorrect (periosteum is outer, not deep; spongy is deep to compact).
• Option d: Incorrect (compact is superficial to spongy, not deep).

Answer:

a. Spongy bone, compact bone, periosteum