Final answer:
The compact bone on the outer surface of bones is known as cortical or compact bone. It forms a dense layer that provides strength and protection, enclosing the medullary cavity and containing important structures such as blood vessels and nerves. The compact bone that makes up the outer surface of bone is called: A) cortical
Step-by-step explanation:
Compact bone, also known as cortical bone, is the dense, hard outer layer of bone tissue that surrounds the medullary cavity. It's composed of tightly packed cells and forms a solid layer of bone, which provides strength and protection. Compact bone houses the Haversian system or osteons, which contain blood vessels and nerves essential for bone health and vitality.
Compared to spongy bone, also known as trabecular bone, which is found inside bones and has a porous structure, cortical bone is more solid and dense, thus ensuring the rigidity and structural integrity of the bones. Additionally, it helps in the support of the body's weight, facilitating movement, and protecting internal organs. Osteoblasts, osteoclasts, and osteocytes are the primary types of cells involved in bone formation and turnover, which are critical for maintaining the strength of the cortical bone.