What is Spongy Bone?

Spongy bone, also called cancellous or trabecular bone, forms the inner layer of flat and irregular bones, such as the vertebrae and sternum. Few of its characteristics are listed below:

• It has a porous and honeycomb-like structure, with interconnecting spaces filled with bone marrow.
• Trabeculae, a network of interconnecting, thin bony struts or plates, are found in porous, flexible bone.
• Its primary function is to provide shock absorption, reduce the weight of bones, and facilitate metabolic exchange between bone cells and the surrounding tissue.
• It contains red marrow, which contains stem cells for Hemopoiesis i.e. formation of blood cells.

Compact and Spongy Bone are two primary types of bone tissues. Compact bone forms the outer layer of long bones and provides strength, support, and protection. On the other hand, spongy bone forms the inner layer of flat and irregular bones and contributes to shock absorption, reducing weight, and facilitating metabolic exchange. These bone structure differences are the reason for the classification.