A porous type of bone tissue, also called cancellous bone, that contains red bone marrow?

• A. Spongy tissue
• B. Compact bone
• C. Yellow bone marrow
• D. Periosteum

Answer: (A)

Spongy tissue describes the porous bone tissue known as cancellous bone. Its structure is a lattice of thin trabeculae with many spaces, making it lighter than dense compact bone. Those spaces are typically filled with red bone marrow, which produces blood cells, so this region is associated with hematopoiesis. Spongy bone is usually found at the ends of long bones and within the interior of bones like the vertebrae, pelvis, and ribs. In contrast, compact bone forms the solid outer layer, yellow bone marrow stores fat and isn’t involved in blood cell production, and the periosteum is the membrane that covers bone. Since the description highlights a porous tissue that contains red marrow, spongy tissue is the best match.