6.4 Bone Structure

Question 1

dense, outer layer of bone; smooth and solid

Answer 1

Compact bone

Question 2

honeycomb of flat pieces of bone deep to compact

-filled with red and yellow marrow

Answer 2

Spongy bone (trabeculae)

Question 3

What cartilage covers articular (joint) surfaces?

Answer 3

Hyaline cartilage

Question 4

elongated shaft of long bone

Answer 4

Diaphysis

Question 5

central cavity of long bone

-contains yellow or red marrow

Answer 5

Medullary cavity

Question 6

the end of the long bone, attached to the shaft

Answer 6

Epiphysis

Question 7

between the diaphysis and each epiphysis of an adult long bone
-a physical division

Answer 7

Epiphyseal line

Question 8

a disc of hyaline cartilage that grows during childhood to lengthen bone

Answer 8

Epiphyseal plate

Question 9

double-layered connective tissue that covers and nourishes the bone

Answer 9

Periosteum

Question 10

dense irregular connective tissue

Answer 10

Outer fibrous layer

Question 11

next to the bone surface; contains osteogenic cells

Answer 11

Osteogenic layer

Question 12

stem cells

Answer 12

Osteogenic cells

Question 13

connective tissue membrane covering internal bone surfaces

• Lines canals that pass through compact bone
• Covers trabeculae of spongy bone

Answer 13

Endosteum

Question 14

red marrow

Answer 14

Hematopoietic tissue

Question 15

secrete osteoid (unmineralized bone matrix) composed of collagen and calcium binding proteins

Answer 15

Osteoblasts

Question 16

mature bone cells in lacunae; monitor and maintain bone matrix

Answer 16

Osteocytes

Question 17

large cells that resorb or break down bone matrix by dissolving calcium and phosphate from bones

Answer 17

Osteoclasts

Question 18

structural unit of compact bone; elongated cylinder parallel to long axis of bone

Answer 18

Osteon/Lamellar bone (Haversian system)

Question 19

hollow tube of bone matrix

-collagen fibers in adjacent rings run in different directions to resist twisting

Answer 19

Lamellae

Question 20

runs through core of osteon; contains blood vessels and nerve fibers

Answer 20

Central (Haversian) canal

Question 21

run at right angles to the central canal; connect blood vessels and nerves of periosteum, medullary cavity, and central canal
-lined with endosteum

Answer 21

Perforating (Volkmann’s) channels

Question 22

small cavities that contain osteocytes

Answer 22

Lacunae

Question 23

hairlike canals that connect lacunae to each other and central canal

Answer 23

Canaliculi

Question 24

1/3 of organic bone matrix secreted by osteoblasts

• made of ground substance (proteoglycans and glycoproteins) and collagen fibers
• provides tensile strength and flexibility

Answer 24

Osteoid

Question 25

65% of bone mass - mainly tiny calcium phosphate crystals in and around collagen fibers - provides hardness and resistance to compression

Answer 25

Hydroxyapatites

Question 26

hydroxyapatites

Answer 26

Mineral salts