Chapter 6 Final Exam

Which is the last phase of endochondral ossification?

An epiphyseal cartilage separates the epiphysis from the diaphysis.

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.

All the following result in decreased calcium levels in the bloodstream EXCEPT __________.

PTH stimulation of osteoclasts

Which statement regarding the internal structure of long bone is correct?

The epiphysis consists largely of trabecular bone.

Which of the following statements regarding the homeostasis regulation of blood calcium is FALSE?

The three main organs that serve as the site for the regulation of blood calcium levels are the bones, the intestines, and the pancreas.

C cells of the thyroid gland secrete which of the following?

calcitonin

Osteoprogenitor cells are characterized by the following EXCEPT __________.

divide to produce daughter cells that differentiate into osteoclasts

A hard ossified bone in an adult actually begins within the embryo as a miniature version composed of __________.

hyaline cartilage

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

Which component is NOT present in spongy bone?

osteons

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

Which structural features of spongy bone are oriented along stress lines and are cross-braced extensively?

trabeculae

During the early stages of endochondral ossification, which cells enlarge, then die and disintegrate?

chondrocytes