What is the primary composition of the forearm in terms of bone type?

• A. 100% trabecular bone
• B. 50% cortical bone
• C. 99% cortical bone
• D. 70% trabecular bone, 30% cortical bone

Answer: (C)

The primary composition of the forearm is largely comprised of cortical bone, which is dense and forms the outer layer of bone structures. Cortical bone accounts for approximately 90-95% of the bone mass in the forearm, particularly in the region of the radius and ulna, the two primary bones in the forearm. This dense, compact bone contributes to the overall strength and stability of the forearm, enabling it to withstand various mechanical stresses.

In contrast, trabecular bone, which is more porous and found in the interior of bones, represents a much smaller portion of the forearm's composition. Because of the forearm's functional requirements, such as supporting movements and loads, the predominance of cortical bone is essential for providing the necessary support and durability.

Thus, the characterization of the forearm being primarily composed of cortical bone provides an accurate reflection of its physical and structural properties, emphasizing its role in supporting skeletal integrity and function.