Final answer:
Spongy bone, also known as cancellous bone, is a flexible bone tissue that contains many small spaces, similar to a sponge. It is found in the inner layer of all bones and does not contain osteons like compact bone.
Step-by-step explanation:
Spongy bone, also known as cancellous bone, is a flexible bone tissue that contains many small spaces, similar to a sponge. It is found in the inner layer of all bones and does not contain osteons like compact bone. Spongy bone consists of trabeculae, which are lattice-like networks of matrix spikes, providing strength to the bone.
The spaces in spongy bone may contain red marrow, where hematopoiesis (formation of blood cells) occurs. Its porous structure makes spongy bone lighter than compact bone and allows for easier movement by muscles.