#4 Bone Formation and Remodeling Flashcards
What is the bone remodeling process?
A continuous process where old bone is replaced with new bone.
What role do osteoclasts play in bone remodeling?
They break down bone, releasing calcium into the bloodstream.
What do osteoblasts do during bone remodeling?
They lay down new bone material.
Approximately what percentage of bone is remodeled each year?
20%.
What is interstitial growth?
Growth that lengthens bones through the epiphyseal plate, where cartilage is replaced by bone.
What is appositional growth?
Growth that increases bone width by adding new bone tissue beneath the periosteum.
What is intramembranous ossification?
Bone develops directly from sheets of mesenchymal connective tissue.
Give an example of bones formed through intramembranous ossification.
Flat bones like the frontal and parietal bones.
What is endochondral ossification?
Bone forms by replacing hyaline cartilage, typical for long bones.
What factors affect bone density?
Mechanical stress and lack of stress.
How does mechanical stress affect bone density?
It increases bone density.
What happens to bone density in bedridden patients or astronauts?
It leads to bone density loss.
What hormones are involved in regulating blood calcium levels?
Parathyroid hormone (PTH) and calcitriol (active vitamin D).
How do PTH and calcitriol work together?
They promote osteoclast activity to increase blood calcium levels.
What nutritional requirements are essential for bone health?
Calcium and vitamin D.
What role does vitamin D play in bone health?
It facilitates calcium absorption in the intestines.
What historical cultural practice altered bone structure?
Foot binding in China.
What modern practice affects foot bone structure?
High-heeled shoes.
What condition results from vitamin D deficiency?
Rickets.
How can lifestyle factors influence bone remodeling?
Through posture and physical activity.
How do orthodontic braces cause tooth movement?
By applying pressure that causes bone remodeling.
What are preventive measures for maintaining healthy bones?
Adequate sunlight exposure and dietary intake of vitamin D and calcium.
