Final answer:
Compact bone, organized into osteons, is a dense matrix that forms the exterior of bones, providing robust structural strength without gaps in its matrix.
Step-by-step explanation:
Compact bone has a continuous extracellular matrix organized into osteons with no gaps. This type of tissue is a dense layer forming the hard exterior of bones, providing structural strength and protecting the marrow cavity. In detail, compact bone, also known as cortical bone, consists of tightly packed osteons or Haversian systems. Each osteon is a cylindrical structure that contains a mineral matrix and living osteocytes connected by canaliculi, which transport blood and nutrients. The osteocytes are situated in cavities called lacunae, and the osteons themselves are aligned parallel to the long axis of the bone, reinforcing it against stress and fracturing.
Surrounding the osteons are concentric rings known as lamellae, and at the center of each osteon is the Haversian canal, housing blood vessels and nerve fibers. Unlike spongy bone with its web-like trabeculae and empty spaces, compact bone is solid with a continuous extracellular matrix that ensures its strength and durability in supporting the body and protecting internal organs.