Ch. 6 Skeletal System

Question 1

Hyaline cartilage

Answer 1

• most intimately associated with bone

- contains perichondrium, chondroblast, lacuna, chondrocyte, matrix

Question 2

Hyaline cartilage

Chondroblast

Answer 2

-produce a matrix surrounding themselves

Question 3

Hyaline cartilage

Chondrocyte

Answer 3

-chondroblast turns into this after the matrix surrounds it

Question 4

Hyaline cartilage

Lacuna

Answer 4

-a rounded cell that occupies space within the matrix

Question 5

Hyaline cartilage

Perichondrium

Answer 5

• double layered connective tissue sheath covering most cartilage
• outside layer

Question 6

Appositional growth

Answer 6

• main area of growth in cartilage

- chondroblasts in the perichondrium ass new cartilage to the outside edge of the existing cartilage

Question 7

Interstitial growth

Answer 7

• very slow process in cartilage

- chondrocytes within the tissue divide and add more matrix between existing cells

Question 8

Bone Anatomy

bone matrix

Answer 8

• a mineral (hydroxyapatite) which is inorganic material of a calcium phosphate crystal
• collagen and proteoglycans is the organic material
• the inorganic and organic materials provide strength

Question 9

Bone Anatomy

osteoblasts

Answer 9

• bone forming cells
• produce collagen and proteoglycans which are packaged into vesicles by the Golgi apparatus and released from the cell by exocytosis

Question 10

Bone Anatomy
matrix vesicles (-blasts)

Answer 10

-membrane bound sacs formed when the plasma membrane buds and pinches off

Question 11

Bone Anatomy

ossification

Answer 11

• osteogenesis

- formation of bone by osteoblasts

Question 12

Bone Anatomy

osteocytes

Answer 12

• all connected, sharing nutrition
• part of a network (communicating cytoplasmically)
• an osteoblast turns to this after becoming surrounded by the matrix

Question 13

Bone Anatomy

canuliculi (-cytes)

Answer 13

-little canals that occupy the spaces by the oseocyte cell process

Question 14

Bone Anatomy

osteoclasts

Answer 14

-responsible for the reabsorption, or breakdown, of bone

Question 15

Bone Anatomy

osteochondral progenitor cells

Answer 15

• mesenchymal stem cells form these which turn into chondroblasts or osteoblasts
• located in the inner layer of the perichondrium and in the layers of connective tissue that cover bone

Question 16

Woven bone

Answer 16

• collegan fibers are randomly oriented in many directions

- quick making of new bone after a breakage

Question 17

Lamellar bone

Answer 17

• mature bone that is organized into thin sheets or layers called lamellae
• woven bone is remodeled into this

Question 18

Spongy bone

Answer 18

-consists of interconnecting rods or plates of bone called trabeculae

Question 19

Spongy bone

trabecula

Answer 19

• there is a limit to size due to blood vessels carrying nutrients
• consists of several lamellae with osteocytes located in lacunae

Question 20

Compact bone

Answer 20

-denser and has fewer spaces than spongy bone

Question 21

Concentric lamellae

Answer 21

-circular layers of bone matrix that surround a common center

Question 22

Circumferential lamellae

Answer 22

• the outer surfaces of compact bone

- thin plates that extend around the bone

Question 23

Interstitial lamellae

Answer 23

-remnants of concentric or circumferential lamellae that were partially removed during bone remodeling

Question 24

Osteon

Answer 24

• haversian system

- consists of a single central canal, its contents and associated concerntric lamellae and osteocytes

Question 25

Perforating canals

Answer 25

-canals that allow blood vessels from the periosteum or medullary cavity enter here

Question 26

Long Bone Structure

diaphysis

Answer 26

-shaft of the bone

Question 27

Long Bone Structure

epiphysis

Answer 27

-part of a long bone that develops from a center of ossification distinct from the diaphysis

Question 28

Long Bone Structure

epiphyseal plate

Answer 28

• area of hyaline cartilage between the diaphysis and epiphysis
• cartilage growth followed by endochondral ossification results in growth in bone length

Question 29

Long Bone Structure

medullary cavity

Answer 29

-large cavity within the diaphysis

Question 30

Long Bone Structure

periosteum

Answer 30

-double layered connective tissue membrane covering the outer surface of bone except where articular cartilage

Question 31

Long Bone Structure

endosteum

Answer 31

-thin connective tissue membrane lining the inner cavities of bone

Question 32

Long Bone Structure

perforating fibers

Answer 32

• bundles of collagen fibers

- strengthen the attachement of the tendons or ligaments to the bone

Question 33

Long Bone Structure

articular cartilage

Answer 33

-thin layer of hyaline cartilage covering a bone where it forms a joint (articulation) with another bone

Question 34

Intramembranous ossification

Answer 34

-takes place in connective tissue membranes

Question 35

Endochondrial ossification

Answer 35

-takes place in cartilage

Question 36

Zone of resting cartilage

Answer 36

-nearest the epiphysis and contains randomly arranged chondrocytes that do not divide rapidly

Question 37

Zone of proliferation

Answer 37

• produce new cartilage through interstitial cartilage growth
• chondrocytes divide and form columns resembling stacks of plates or coins

Question 38

Zone of hypertophy

Answer 38

• chondrocytes produced in the zone of proliferation mature and enlarge
• a maturation gradient exists in each column

Question 39

Zone of calcification

Answer 39

-very thin and contains hypertrophied chondrocytes and calcified cartilage matrix

Question 40

Parathyroid hormone (PTH)

Answer 40

• one hormone that maintains calcium homeostasis
• major regulator of blood Ca 2+ levels
• secreted from the parathyroid glands when blood Ca 2+ levels are too low

Question 41

Calcitonin

Answer 41

• one hormone that maintains calcium homeostasis

- secreted from the thyroid gland when blood Ca 2+ levels are too high