2.1.1 Bone anatomy
About 80% of the body’s bone is cortical, with a long bone like the femur arranged as a cylinder of cortical bone around a core of trabecular bone and marrow. [image as previous]
However some bones, like the spinal vertebrae, constitute predominantly trabecular bone. The strength of trabecular bone depends on the connectivity of the trabeculae.
Bone tissue is a matrix of collagen protein, with minerals, especially calcium, which make the matrix rigid. There are bone cells embedded within this matrix. They make a unit of cells (the basic multicellular unit = BMU) which creates controls and repairs the matrix.
There are 3 cell types in this cellular network of bone:
Osteoblasts: these create new bone by secreting matrix.
Osteoclasts: these resorb old or damaged bone, by dissolving it.
Osteocytes: these sense bone loading and orchestrate the activities of the other cells
2.1 Bone metabolism and structure