The remnant of the childhood bone growth zone at the junction of the epiphysis and diaphysis is called the

• A. Epiphyseal line
• B. Diaphysis
• C. Diploe
• D. Endosteum

Answer: (A)

The remnant of the childhood growth zone at the junction of the epiphysis and diaphysis is the epiphyseal line. During growth, a cartilage layer called the epiphyseal plate sits between the ends of the bone, allowing lengthwise growth as cartilage is gradually replaced by bone. When growth stops, this plate ossifies and a thin bony line remains where it used to be—the epiphyseal line. The other terms describe different bone features: the diaphysis is the shaft of a long bone, the diploe is the spongy middle layer in flat bones, and the endosteum lines the inner surfaces of bone cavities.