Bone and bone growth Flashcards
What are the 3 main areas of a long bone?
epiphysis
diaphysis
periosteum
What are the two types of bone?
compact
cancellous/spongy
What are osteoblasts?
cover the surface of bone and are responsible for bone formation
What are osteocytes?
maintain bone matrix through cell to cell communication and influence bone remodelling
What are osteoclasts?
reabsorb bone matrix in response to mechanical stresses and physiological demands - regulated by osteoblasts
What are fibroblasts?
produce collagen and other fibres
How does fracture healing work?
- osteoblasts quickly form woven bone to bridge the gap
- osteoclasts can remodel to restore the original bone shape
What is ossification?
old bone is continuously removed by osteoclasts and replaced by osteoblasts
What is hypertrophy?
when bone is made
What is atrophy?
when bone is lost
How is equilibrium between osteoblast and osteoclast activity controlled?
- calcitonin decreases the activity of osteoclasts
- parathyroid hormone increases the activity of osteoclasts and releases Ca+
What are the 4 stages of the bone remodelling cycle?
quiescence
resorption
reversal
formation
What does Wolff’s law state?
how bone adapts to the load under which it is placed
Where does ossification begin?
the diaphysis
