Defective mineralization: osteoid in adults (osteomalacia) vs physis in children (rickets). Etiologies: Vit D deficiency/resistance, phosphate deficie...
Excess PTH causes cortical bone loss via RANKL-mediated osteoclast activation; classic radiology: subperiosteal resorption, salt‑and‑pepper skull, bro...
Brachial plexus consists of Roots (C5–T1), Trunks (upper, middle, lower), Divisions (each trunk splits into anterior/posterior), Cords (lateral, poste...