Bone and Osteopersosis Flashcards
What is osteoporosis, and why is it a concern?
Osteoporosis is a condition characterized by reduced bone mass and structural deterioration, leading to increased fracture risk. It often remains symptomless until a fragility-related fracture occurs.
What role does estrogen play in bone health?
Estrogen helps block bone resorption, promotes bone growth during childhood and puberty, and prevents excessive bone loss in adults. Its decline during menopause accelerates bone loss.
How does exercise benefit bone health?
Exercise strengthens bones by increasing mechanical stress, promoting the deposition of mineral salts and collagen production, and enhancing overall bone density.
What is the mechanostat theory?
The mechanostat theory states that bone adapts to mechanical load; increased load promotes bone formation, while reduced load leads to bone resorption.
Bone composition is ~70% inorganic salts (hydroxyapatite) and
~30% organic matrix (95% collagen).
RANKL stimulates osteoclast activity, while
OPG inhibits RANKL to reduce bone loss.
OPG inhibits RANKL to reduce bone loss.
suffer a fragility-related fracture.
High-impact exercises like jumping and resistance training significantly
increase bone mineral density (BMD).
Dual-energy X-ray absorptiometry (DEXA) is the gold standard for
diagnosing osteoporosis
Walking alone is sufficient to significantly improve lumbar spine BMD.
False. Walking does not provide enough mechanical stress to trigger significant changes in lumbar spine BMD.
Mechanical stress increases calcitonin levels, reducing bone resorption.
True
Osteoporosis is diagnosed using ______, which measures bone mineral density.
DEXA (Dual-energy X-ray absorptiometry).
The bone-specific alkaline phosphatase (BAP) is a biomarker for ______ activity.
Bone formation
______ is a cytokine that stimulates osteoclasts, while ______ inhibits its action to reduce bone loss.
RANKL, OPG.
Which exercise is most effective for increasing BMD in weight-bearing bones?
A. Cycling
B. Swimming
C. Jumping
D. Yoga
C. Jumping
What is the primary function of osteoblasts?
A. Break down bone
B. Produce collagen and mineralize the bone matrix
C. Inhibit bone remodeling
D. Reduce inflammation
B. Produce collagen and mineralize the bone matrix.
Scenario: Jane, a postmenopausal woman, is concerned about osteoporosis. She considers starting a walking routine to improve bone health.
Q: What would you recommend to optimize her bone health?
A: While walking can help maintain bone health, adding high-impact or resistance exercises like weightlifting or jumping would be more effective in increasing BMD and reducing fracture risk.
Scenario: Mark, a sedentary office worker, starts resistance training twice a week.
Q: How will this affect his bone health?
A: Resistance training will increase mechanical stress on his bones, promoting bone formation, improving BMD, and reducing the risk of osteoporosis-related fractures.
Bone Remodeling:
he continuous process of bone resorption by osteoclasts and bone formation by osteoblasts, essential for maintaining bone strength and calcium homeostasis.
RANKL:
A cytokine that activates osteoclasts for bone resorption.
OPG (Osteoprotegerin):
A decoy receptor that binds RANKL, inhibiting its action to reduce bone resorption.
T-score:
Measures how far BMD deviates from a young, healthy reference population.
Z-score:
Measures how far BMD deviates from a same age reference population.
BMD (Bone Mineral Density):
A measure of bone strength and a diagnostic marker for osteoporosis.
