Ключевые слова: aging, anatomy, background, biology, blood, body, bone, brittle, calcium, care, cartilage, close, comparing, density, diagram, disease, fracture, fragility, health, healthy, holes, human, illustration, inside, joint, loss, macro, marrow, medical, medicine, microscopic, normal, old, orthopedic, osteoporosis, porous, rendering, schematic, science, simplified, skeletal, skeleton, spongy, stages, structure, tissue, unhealthy, white,