Describe the structure of spongy bone. What are trabeculae, and what is their function? How do osteocytes
within trabeculae obtain nutrients?
The Correct Answer and Explanation is :
Structure of Spongy Bone
Spongy bone, also known as cancellous bone, is a porous, lightweight form of bone tissue found primarily in the interior of bones. Unlike the dense and solid structure of compact bone, spongy bone consists of a network of bony struts called trabeculae, which create an open, lattice-like framework. This structure allows spongy bone to provide support while reducing the overall weight of the skeleton, making movement more efficient.
Trabeculae and Their Function
Trabeculae are thin, interconnecting plates of bone that form the structural framework of spongy bone. These trabeculae align along lines of mechanical stress, which helps distribute forces evenly across the bone, enhancing its strength and resistance to stress. This adaptation is particularly important in weight-bearing bones, such as the vertebrae, femur, and pelvis, where forces from movement and impact must be absorbed and dispersed.
The primary functions of trabeculae include:
- Providing structural support while minimizing weight.
- Absorbing and distributing mechanical forces to prevent fractures.
- Housing bone marrow, which is crucial for blood cell production.
Nutrient Supply to Osteocytes
Unlike compact bone, which has a centralized Haversian system for nutrient distribution, spongy bone lacks osteons and instead relies on diffusion for nutrient transport. Osteocytes within trabeculae are embedded in small cavities called lacunae and receive nutrients through canaliculi, tiny channels that connect neighboring cells. These nutrients come from blood vessels in the surrounding bone marrow, which is located in the spaces between trabeculae. This arrangement allows for efficient exchange of nutrients and waste, ensuring the survival and function of bone cells.
Now, I’ll generate an image illustrating the structure of spongy bone and trabeculae.
Here is the generated illustration of spongy bone, showing its trabecular structure, osteocytes, lacunae, canaliculi, and blood vessels. Let me know if you need any modifications or explanations!