What is spongy bone and where is it located?

• A. Also called cancellous bone; made of trabeculae with many spaces; located in the epiphyses of long bones and inside some flat bones; lighter and houses marrow.
• B. Dense compact bone lining outer surfaces.
• C. Compact bone found in the medullary cavity.
• D. Cartilage only, with no bone tissue.

Answer: (A)

Spongy bone, also called cancellous bone, is a porous lattice made of trabeculae with many small spaces. This lighter, open structure reduces weight and creates room for bone marrow, which is where blood cells form. It’s typically found toward the ends of long bones (the epiphyses) and inside some flat bones, nestled beneath a thin outer layer of compact bone. The spaces within spongy bone can contain red marrow in younger individuals and sometimes yellow marrow later on. This contrasts with dense compact bone, which forms the solid outer shell, and with cartilage, which is a different tissue altogether.