In endochondral ossification, which zone of the epiphyseal plate (growth plate) contains hypertrophied chondrocytes undergoing calcification and is the zone targeted by the metaphyseal blood supply?

• A Zone of resting (reserve) cartilage
• B Zone of proliferating cartilage
• C Zone of hypertrophy (maturation)
• D Zone of calcification (provisional calcification) ✓

Explanation

The epiphyseal plate has four zones from epiphysis to metaphysis: resting (stem cells), proliferating (rapid mitosis), hypertrophic (chondrocyte enlargement and matrix secretion), and calcification (calcified cartilage matrix). It is the zone of provisional calcification that is invaded by metaphyseal blood vessels and osteoprogenitor cells, allowing conversion of calcified cartilage to primary spongiosa (woven bone). This zone is selectively vulnerable to disruption in rickets (inadequate mineralization), causing widening of the growth plate.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.