A model specifically designed to illustrate loss of bone mass; the progressive reduction in bone density and resulting atrophy which can be most often seen with postmenopausal women. This series consists of three medially sectioned lumbar vertebrae and their intervertebral discs. The topmost vertebra exhibits normal healthy bone structure. The middle reflects the increased porosity and loss of bone mass characterizing the osteoporotic condition. Finally, in advanced osteoporosis, the bottom vertebra manifests deterioration, deformation, flattened plates and greatly reduced bone density. Detachably mounted on a support base.