Spongy bone

Definition

Spongy bone, also known as cancellous bone, is a type of bone tissue that has a porous structure and is found primarily at the ends of long bones and in the interiors of others. It plays a crucial role in the overall strength and flexibility of the skeleton while reducing the weight of bones, making them easier to move. The open spaces within spongy bone are filled with bone marrow and blood vessels, which are essential for producing blood cells and providing nutrients to the bone tissue.

5 Must Know Facts For Your Next Test

1. Spongy bone is less dense than compact bone, allowing it to absorb shock and distribute forces applied to the skeleton more effectively.
2. The trabecular structure of spongy bone consists of a network of small rod-like or plate-like elements called trabeculae, which help maintain structural integrity.
3. Spongy bone contains red marrow, which is involved in hematopoiesis, the process of blood cell formation.
4. In addition to providing support, spongy bone aids in reducing the overall weight of bones, which contributes to greater mobility.
5. The architecture of spongy bone can adapt over time in response to stress and strain, demonstrating its dynamic nature in response to physical activity.

Review Questions

• How does the structure of spongy bone contribute to its function in the human skeleton?
  • The structure of spongy bone, characterized by its porous and trabecular design, contributes significantly to its function by allowing it to absorb impact and distribute mechanical stress throughout the skeletal system. The open spaces filled with marrow enable vital processes such as blood cell production while keeping bones lighter and more manageable for movement. This combination of strength and flexibility makes spongy bone essential for maintaining overall skeletal health.
• Discuss the differences between spongy bone and compact bone in terms of structure and function.
  • Spongy bone and compact bone differ primarily in their structure; spongy bone has a porous, lattice-like arrangement while compact bone is dense and solid. Functionally, compact bone provides strength and protection to bones, while spongy bone offers flexibility and support without adding significant weight. Additionally, spongy bone plays an essential role in hematopoiesis due to its marrow content, contrasting with compact bone's primary focus on structural integrity.
• Evaluate how changes in physical activity levels can affect the density and architecture of spongy bone over time.
  • Changes in physical activity levels can significantly impact the density and architecture of spongy bone due to its adaptive nature. Increased physical activity leads to higher mechanical stress on bones, which stimulates osteoblast activity to build new bone tissue, thus enhancing density and strength. Conversely, reduced activity may lead to decreased stimulation of osteoblasts, resulting in a loss of density and structural integrity over time. This demonstrates the importance of maintaining an active lifestyle for optimal skeletal health.

Related terms

Compact Bone: The dense and solid outer layer of bone that provides strength and structure, forming the bulk of the diaphysis of long bones.

Bone Marrow: The soft, flexible tissue found within the cavities of bones that is responsible for producing blood cells, including red blood cells, white blood cells, and platelets.

Osteocytes: Mature bone cells that are embedded within the bone matrix and play a key role in maintaining bone tissue and regulating mineral content.