chap 6: bone and bone structure

Which is the last phase of endochondral ossification? A primary ossification center is formed. An epiphyseal cartilage separates the epiphysis from the diaphysis. Chondrocytes near the center of the shaft increase greatly in size. A secondary ossification center is formed.

An epiphyseal cartilage separates the epiphysis from the diaphysis

What is responsible for appositional growth? Bone is deposited by superficial osteoblasts. Bone is deposited by superficial osteoclasts. Bone matrix is removed by osteoblasts. Medullary cavity pushes the osteons outward.

Bone is deposited by superficial osteoblasts

Which condition, due to excessive cartilage formation at the epiphyseal cartilages, results in individuals who are very tall, with long, slender limbs? gigantism Marfan syndrome achondroplasia acromegaly

Marfan syndrome

All the following result in decreased calcium levels in the bloodstream EXCEPT __________. decreased PTH or calcitriol levels increased calcitonin levels PTH stimulation of osteoclasts calcitonin inhibition of osteoclasts

PTH stimulation of osteoclasts

C cells of the thyroid gland secrete which of the following? PTH calcium calcitonin calcitriol

calcitonin

Which substance accounts for almost two-thirds of the weight of bone? calcium salts osteocytes fibroblasts collagen fibers

calcium salts

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

chondrocytes

To form perforating fibers, osteoblasts from the cellular layer of the periosteum cement collagen fibers from tendons, ligaments, and joint capsules into which structures? interstitial lamellae central canal concentric lamellae circumferential lamellae

circumferential lamellae

Which bone is NOT formed via intramembranous ossification? clavicle mandible femur patella

femur

Ectopic bones may occur in which of the following conditions? acromegaly gigantism fibrodysplasia ossificans progressiva (FOP) Marfan syndrom

fibrodysplasia ossificans progressiva (FOP)

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

mesenchymal cells

The periosteum contains all the following EXCEPT __________. lymphatic vessels blood vessels sensory nerves motor nerves

motor nerves

The process of osteolysis is performed by which cell population? osteoprogenitor cells osteocytes osteoclasts osteoblasts

osteoclasts

Which component is NOT present in spongy bone? osteons lamellae trabeculae canaliculi

osteons

Which class of bones develops inside tendons and is most commonly located near joints at the knees, the hands, and the feet?

sesamoid bones

What supplies the articular cartilage of long bones with oxygen and nutrients? metaphyseal artery epiphyseal artery synovial fluid nutrient artery

synovial fluid

Which structural features of spongy bone are oriented along stress lines and are cross-braced extensively? trabeculae canaliculi perforating canals concentric lamellae

trabeculae

Which of the following is not a surface feature of the pelvis?

trochanter