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Basic Science
intermediate
X-Type

Osteoclasts and Bone Resorption - RANKL, OPG, and Bisphosphonates

Bone Biology and Metabolism

A 72-year-old postmenopausal woman with osteoporosis (T-score -3.2) is being counselled about treatment options. She has sustained a Colles' fracture after a fall from standing height. Her medical history includes gastro-oesophageal reflux disease. The orthopaedic surgeon discusses the mechanisms of bone resorption and available therapies targeting this pathway. Regarding osteoclast biology and the RANK/RANKL/OPG pathway:

Mark each as TRUE or FALSE

A

Osteoclasts are derived from HAEMATOPOIETIC stem cells of the monocyte/macrophage lineage; they are ...

B

The RUFFLED BORDER is the resorptive surface with deep membrane foldings; the SEALING ZONE (clear zo...

C

Osteoclasts are derived from MESENCHYMAL stem cells like osteoblasts; they are MONONUCLEAR cells; th...

D

RANKL (Receptor Activator of Nuclear factor Kappa-B Ligand) is produced by OSTEOBLASTS and OSTEOCYTE...

E

M-CSF (Macrophage Colony-Stimulating Factor) is also required for osteoclast differentiation (binds ...

Answer the questions to see explanations

Click T (True) or F (False) for each option