Chapter 6

Question 1

Bone

Answer 1

Organ made of osseous tissue, cartilage, dense connective tissue, epithelium, adipose tissue and nervous tissue

Question 2

Skeletal system

Answer 2

Framework of bones and their cartilage

Question 3

Function of skeletal system

Answer 3

Support
Protection
Assistance in moving
Mineral homeostasis
Blood cell production
Triglyceride storage

Question 4

Diaphysis

Answer 4

Bone’s shaft/body
Long cylindrical main portion of bone

Question 5

Epiphyses

Answer 5

Proximal and distal ends of the bone

Question 6

Metaphyses

Answer 6

Region between diaphysis and epiphysis

Question 7

Epiphyseal plate

Answer 7

In metaphyses of growing bone
Layer of hyaline cartilage that allows for diaphysis to grow in length

Question 8

Epiphyseal Line

Answer 8

Replaces Epiphyseal plate when bone stops growing

Question 9

Articulate cartilage

Answer 9

Thin layer of hyalin cartilage covering parts of epiphyses where bones form joints

Question 10

Periosteum

Answer 10

Tough connective tissue sheath and associated blood supply cover wherever articulat cartilage isn’t

Question 11

Periosteum outer fibrous layer

Answer 11

Made up of dense irregular connective tissue

Question 12

Periosteum osteogenic layer

Answer 12

Consists of cells that allow for growth in width of bone

Question 13

Function of periosteum

Answer 13

Protects bone
Assists in fracture repair
Nourish bone tissue
Attachment points for ligaments and tendons

Question 14

Perforating fibers(Sharpey’s fibers)

Answer 14

Attaches periosteum to underlying bone

Question 15

Medullary Cavity (Marrow Cavity)

Answer 15

Hollow, cylindrical space writhing diaphysis, has yellow bone marrow and blood vessels

Question 16

Endosteum

Answer 16

Thin membrane made of a single layer of bone forming cells and a small amount of connective tissues.
Line the medullary cavity

Question 17

Hydroxyapatite

Answer 17

Made up of calcium phosphate and calcium hydroxide
Bone strength and regen

Question 18

Calcification

Answer 18

Crystals form from mineral salt deposits in framework of collagen fibers of extracellular matrix hardens the tissue
Initiated by osteoblasts

Question 19

4 types of cells in bone tissue

Answer 19

Osteoprogenitor cells
Osteoblasts
Osteocytes
Osteoclasts

Question 20

Osteoprogenitor Cells

Answer 20

Unspecialized bone stem cells from mesenchyme
Only cells that undergo cell division

Question 21

Osteoblasts

Answer 21

Bone building cells
Synthesizes and secretes collagen fibers and other substances to build extracellular matrix

Question 22

Osteocytes

Answer 22

Mature bone cells
Maintain metabolism by exchanging nutrients and waste
No cell division

Question 23

Osteoclasts

Answer 23

Huge cell formed by fusion of many monocytes
Located in endosteum
Part of bone resorption

Question 24

Compact bone

Answer 24

Strongest form of bone tissue
Made up of Osteons
Protection, support and resisting stress of weight and movement

Question 25

Interstitial lamellae

Answer 25

Area between neighbouring osteons Fragments of older osteons that were partially destroyed during bone building or remodelling

Question 26

Interrosteonice canal

Answer 26

Where blood vessels and nerves from periosteum penetrate compact bone Connect medullary cavity, periosteum and central canal

Question 27

Circumferential lamellae

Answer 27

Lamellae arranged around outer and inner circumference of shaft of long bone

Question 28

External circumferential lamellae

Answer 28

Deep to periosteum Connects periosteum and perforating fibers

Question 29

Internal circumferential lamellae

Answer 29

Circumferential lamellae that line medullary cavity

Question 30

Spongy bone tissue

Answer 30

Located in interior of bone and protected by layer of compact bone Make up interior of short, flat, sesamoid and irregular shaped bones

Question 31

Trabecula

Answer 31

Lamellae arranged in irregular pattern of thin columns Orient along stress lines

Question 32

Hemopoiesis in adults

Answer 32

Only places where red blood cells are produced in adults Hips, ribs, sternum, vertebrae, proximal end of humerus, femur =Sites where red bone marrow is stored

Question 33

Ossification

Answer 33

Process by which bone is made

Question 34

Initial bone formation in Embryo and Fetus

Answer 34

Embryonic skeleton composed of mesenchyme

Question 35

Intramembraneous ossification

Answer 35

Bone forms directly inside mesenchyme Assembled in sheets and resembles membrane

Question 36

Endochondral ossification

Answer 36

Bone forms within hyalin cartilage and develops from mesenchyme

Question 37

Intramembranous Steps

Answer 37

Development of ossification centre Calcification Formation of trabeculae Development of periosteum

Question 38

Steps of Endochondral Ossification

Answer 38

Development of cartilage model Growth of cartilage model Development of primary ossification center Development of secondary ossification centre Formation of articulation cartilage and Epiphyseal plate

Question 39

4 zones of Epiphyseal plate

Answer 39

Zone of resting cartilage Zone of proliferation cartilage Zone of hypertrophic cartilage Zone of calcified cartilage

Question 40

Zone of resting cartilage

Answer 40

Layer closest to epiphysis Cells do not function in bone growth, they anchor Epiphyseal plate to epiphysis

Question 41

Zone of proliferating cartilage

Answer 41

Chondrocytes arranged in stacks of coins Undergo interstitial growth as they divide and secrete extracellular matrix

Question 42

Zone of hypertrophic cartilage

Answer 42

Consists of large, maturing chondrocytes arranged in columns

Question 43

Zone of calcified chondrocytes

Answer 43

Final zone Mostly dead chondrocytes Osteoblasts enter from area cleared by osteoclasts and lay down extracellular matrix and replacing calcified cartilage

Question 44

Remodelling of bone

Answer 44

Ongoing replacement of old bone tissue by new bone tissue

Question 45

Bone deposition

Answer 45

Addition of minerals and collagen fibers by osteoblasts

Question 46

Factors affecting bone growth and remodelling

Answer 46

Minerals Vitamins Hormones

Question 47

Insulin-like growth factor

Answer 47

Hormone in childhood Stimulates osteoblasts, promotes cell division at Epiphyseal plate and in periosteum and enhances synthesis of proteins needed to build new bone

Question 48

Thyroid hormones

Answer 48

T3 and T4 Promote growth by stimulating osteoblasts

Question 49

Insulin

Answer 49

Promotes growth by increasing synthesis of bone proteins

Question 50

Sex hormones

Answer 50

Estrogen and androgens Increase osteoblasts activity, synthesis of extracellular matrix Shut down Epiphyseal plate

Question 51

Sex hormones in adulthood

Answer 51

Contribute of bone remodelling by slowing resorption of old bone and promoting deposition of new