CSB520 (Week 9) Exam Study Guide.

©BRIGHTSTARS EXAM SOLUTIONS 11/16/2024 10:16 AM 1 | P a g e CSB520 (Week 9) Exam Study Guide. Define bone cells - answer(1) osteoblasts - bone-forming cells - related to fibroblasts, chondrocytes and adipocytes/ unrelated to osteoclasts (2) osteocytes - related to osteoblasts/ unrelated to osteoclasts (3) osteoclasts - bone-reabsorbing cells - unrelated to osteoblasts Define bone matrix - answer(1) matrix proteins - osteoid (unmineralised bone matrix composed of type 1 collagen and proteoglycans) - provides bone flexibility (2) minerals - calcium hydroxyapatite - provides bone strength What 3 cells are a part of the osteoblast family? - answer(1) osteoblasts - form bone matrix (2) osteocytes - form interconnecting network throughout bone matrix (3) lining cells - cover metabolically inactive bone surfaces What are the 2 types of bone? - answer(1) cortical ©BRIGHTSTARS EXAM SOLUTIONS 11/16/2024 10:16 AM 2 | P a g e - compact bone (thick and dense) - structural function (2) trabecular (cancellous) - spongy bone (thin and porous) - metabolic function and some structural function bone remodelling** - answerThe continuous turnover of bone matrix and mineral that involves first, an increase in resorption and osteoclast activity, and later, reactive bone formation by osteoblast activity. What are the 3 functions of bone remodelling?** - answer- continually release minerals to maintain appropriate serum levels - maintain structural integrity of bone - allow changes in bone structure in response to growth and altered weight bearing What is the process of bone remodelling? - answer(1) activation - osteoblasts activate osteoclasts to reabsorb old bone (2) reabsorption - osteoclasts reabsorb old bone (3) reversal - osteoblasts replace old bone being absorbed by osteoclasts (4) formation - osteoblasts form new bone BONE DEVELOPMENT - answer(1) endochondrial ossification (forms by replacing hyaline cartilage) - hyaline cartilage is replaced by bone at epiphyseal growth plates (cartilage persists until adolescence) - bones of long bones, vertebrae and pelvis ©BRIGHTSTARS EXAM SOLUTIONS 11/16/2024 10:16 AM 3 | P a g e (2) intramembranous ossification (forms directly from mesenchymal connective tissue) - woven bone (mesenchymal or undifferentiated connective tissue) matures into compact bone - bones of skull Define peak bone mass - answer- measure of amount of bone mass (and strength) at end of bone development - low peak bone mass increases risk of osteoporosis (which increases risk of pathological fracture) What 3 factors determine peak bone mass? - answer(1) physical activity (2) genetic factors (3) nutrition What other factors determine peak bone mass?** - answer- fat - oestrogen and testosterone - growth hormone Define osteoporosis - answerdecreased bone mass What are the risk factors for osteoporosis? - answer- increasing age - lack of physical activity - female gender (decreased oestrogen due to (1) amenorrhea or (2) menopause) - low initial bone mass What factors increase bone loss? - answer(1) glucocorticoids or corticosteroids (anti- inflammatory drugs) (2) NSAIDS (3) amenorrhea (loss of menstrual cycle) (4) reduced muscle mass What factors increase bone formation? - answer(1) testosterone (2) oestrogen (3) weight-training