Solution

Low estrogen and excess PTH both cause bone loss.

Estrogen promotes the activity of osteoblasts and inhibits osteoclasts. In an ageing female, osteoporosis occurs due to deficiency of estrogen. Parathormone promotes mobilisation of calcium from bone into blood. Excessive activity of parathormone causes demineralisation, leading to osteoporosis.

Concept osteoporosis-hormones

Chemical Coordination and Integration in past papers

85 questions from this chapter have appeared across 26 exam years.