PHAR 451 Lecture Notes - Lecture 1: Dual-Energy X-Ray Absorptiometry, Pathologic Fracture, Medical Ultrasound
Document Summary
Effects of estrogens and androgens on bone remodelling. Androgens and estrogens inhibit both osteoblasts and osteoclasts, but they have the most effect on ocs. They increase osteoclast apoptosis, inhibit apoptosis of obs. If you have less estrogen, you have more ocs and less obs. Changes in bone mass with age in men and women with age. Increase osteoclast activation and recruitment: large increase in the bmu activation frequency. Reduced osteoclast apoptosis: increased erosion depth by prolonging the resorption phase. Decreased activity and increased apoptosis of osteoblasts: bone formation cannot keep pace with bone resorption. If you have a low peak bone mass, then it is a risk factor for getting osteoporosis in the future. It"s not just how fast you losee bmd but also where you start from. Heredity, gender, mechanical forces, hormones, nutrution, risk factors. You start with mesenchymal stem cells which are multipotent and can become stromal cells or fat cells.