Ch. 6 Post-Lecture

What is responsible for appositional growth?

Bone is deposited by superficial osteoblasts.

Bill, age 15, is still growing, but his older sister Andrea, age 19, has stopped. What has changed in Andrea's bones?

Her epiphyseal plates have ossified.

Which substance accounts for almost two-thirds of the weight of bone?

calcium salts

In intramembranous ossification, which cells first cluster together and start to secrete the organic components of the matrix?

mesenchymal cells

Cells of the perichondrium need to take on a new role as ossification begins. They will become __________.

osteoblasts and begin to deposit bone matrix

The process of osteolysis is performed by which cell population?

osteoclasts

As blood vessels extend into the spaces left by dying chondrocytes, the models begin to ossify internally. Where does internal ossification begin?

the primary ossification center in the diaphysis