kortikaaliluuta

Kortikaaliluuta, also known as cortical bone or compact bone, is the dense outer layer of bone tissue in vertebrates. It forms the shaft of long bones and the outer surface of all other bones. This hard, rigid structure provides strength and support to the skeleton, protecting internal organs and facilitating movement.

Microscopically, kortikaaliluuta is composed of tightly packed structural units called osteons, or Haversian systems. Each osteon consists of concentric lamellae, which are layers of bone matrix, surrounding a central Haversian canal. This canal contains blood vessels and nerves that supply nutrients and innervate the bone tissue. The lamellae are mineralized with calcium salts, primarily hydroxyapatite, which gives bone its hardness. Osteocytes, mature bone cells, are embedded within the lacunae between the lamellae, connected by tiny channels called canaliculi that allow for communication and nutrient exchange.

Kortikaaliluuta plays a crucial role in bone remodeling, a continuous process of bone breakdown and formation. This remodeling allows bone to adapt to mechanical stresses and repair microdamage. The density and thickness of kortikaaliluuta vary depending on the bone's location and the mechanical demands placed upon it. For instance, weight-bearing bones like the femur have significantly thicker kortikaaliluuta compared to less stressed bones. Its maintenance is vital for skeletal integrity and overall health.