bone

Question 1

The most dynamic structure in the body; greatly affected by nutritional and metabolic changes.

Answer 1

bone

Question 2

A reservoir for calcium and phosphorus that undergo a constant flux in and out of the bone matrix.

Answer 2

bone

Question 3

how does the bone respond to injury

Answer 3

by rapid healing

Question 4

undergoes internal remodeling throughout life without changing its gross apeparance

Answer 4

bone

Question 5

Bone cells are in contact with each other through cellular processes embedded in tiny channels in the hard bone matrix called

Answer 5

canaliculi

Question 6

form a system of channels that provide a route by which processes from one osteocyte can contact those of adjacent ones and allow osteocytes to communicate with one another for passage of information, nutrients, and/or wastes from cells near blood vessels to the ones trapped in lacunae.

Answer 6

canaliculi

Question 7

highly vascular and grows only by appositional method

Answer 7

bone

Question 8

why do bones cannot grow interstitially

Answer 8

because of its rigidity due to mineralization

Question 9

functions of bones

Answer 9

forms the skeleton of the body
provides attachment sites for muscles and constitutes the structural framework of the thoracic and abdominal cavities

Question 10

it houses haemopoietic tissue and serves as reservoir for various minerals

Answer 10

bone

Question 11

2 division of functions of bones

Answer 11

support and metabolism

Question 12

the connective tissue sheath of bone which influences the function of bone

Answer 12

periosteum

Question 13

the 2 components of the periosteum a

Answer 13

outer fibrous layer and inner osteogenic layer

Question 14

composed of regular DWFCT (collagen fibers) and fibroblast

Answer 14

outer fibrous layer of periosteum

Question 15

composed of stellate or spindle shaped osteogenic cells from the fibroblast cell line.

Answer 15

inner osteogenic layer of periosteim

Question 16

surrounds the bone, except at articular surfaces and at many sites of muscle attachment

Answer 16

periosteum

Question 17

the contents of the periosteum for maintenance of the underlying bone

Answer 17

sensory nerve fibers and a dense network of blood and lymphatic vessels

Question 18

capable of rapidly producing new bone tissue,

Answer 18

the pluripotent osteogenic layer of periosteum

Question 19

Bone cavities and canals are lined by

Answer 19

endosteum

Question 20

this is much thinner than periosteum and outer fibrous layer is loose connective tissue rwathher than dwct

Answer 20

endosteum

Question 21

responsible for internal remodelling of bone

Answer 21

endosteum

Question 22

bone is derived from the

Answer 22

mesencgymal connective tissue

Question 23

bone is consist of

Answer 23

bone cells and bone matrix

Question 24

principal component of bone

Answer 24

intercellular substance

Question 25

it gives bone the ability to to ressist snapping and breaking

Answer 25

collagen fibers

Question 26

(20-30% of total organic material of bone

Answer 26

collagen fibers a

Question 27

proteoglycans attached with GAGs

Answer 27

amorphous gel like matrix

Question 28

the unmineralized matrix of the bone.

Answer 28

osteoid

Question 29

form the osteoid

Answer 29

amorphous substance and collagen fibers

Question 30

gives bones its hardness and rigidity

Answer 30

mineralized osteoid

Question 31

mineralization of osteoid is chiefly from

Answer 31

calcium phosphate and hydroxyl ions

Question 32

type of bones has 65% mineral content and 35% amorphous substance and collagen.

Answer 32

mature

Question 33

matrix component which is a gelatinous mucopolysaccharide that binds the proteoglycans together into large aggregates.

Answer 33

hyaluronic acid

Question 34

what type of collagen predominates in the matrix of the bone

Answer 34

type 1

Question 35

what type of collagen is present in the bone

Answer 35

2,3,5,10

Question 36

form the mineral component of bone

Answer 36

Inorganic salts which range from calcium and phosphate ions to more complex hydroxyapatite

Question 37

located in the holes and pores of the matrix collagen fibers

Answer 37

calcium salts

Question 38

Due to ______, the matrix of bone is poorly permeable to most nutrients which must subsequently reach bone cells by flowing through the lacunar-canalicular system.

Answer 38

calcification

Question 39

boen cell components

Answer 39

osteoprogenitor cells, osteoblasts, bone-lining cells, osteocytes and osteoclasts.

Question 40

Except for _____, cells found in bone represent different functional phases of the same cell type

Answer 40

osteoclast

Question 41

Osteoprogenitor cells differentiate into

Answer 41

osteoblasts

Question 42

these are bone forming cells

Answer 42

osteoblast

Question 43

synthesise the organic components of the bone matrix.

Answer 43

osteoblasts

Question 44

when do osteoblast become osteocytes

Answer 44

after mineralization of the matrix

Question 45

e responsible for bone resorption.

Answer 45

osteoclast

Question 46

where do osteoprogenitor cells develop form

Answer 46

mesenchymal stem cells

Question 47

, these are flattened cells with pale cytoplasm and an ovoid to oblong nucleus

Answer 47

osteoprogenitor cells

Question 48

osteoprogenitor cells are found predominantly in the

Answer 48

osteogenic layer of the periosteum and along vessels of the bone marrow

Question 49

what component of bone does not undrgo mitosis

Answer 49

osteoblast

Question 50

different ways in which the osteoblast participate in the bone formation

Answer 50

synthesis of type I collagen fibers, non-collagenous proteins, production of glycosaminoglycans/proteoglycans, participation in mineralisation of bone matrix and modulation of osteoclast function.

Question 51

the youngest and only bone cell capable of mitosis

Answer 51

osteogenic cells

Question 52

type of bone cells that is spindle or stellate shaped with round or oval nuclei

Answer 52

osteogenic

Question 53

secretes osteoid at the periphery of the bone trabecula and later, hydroxypatite to harden the osteoid

Answer 53

osteoblasts

Question 54

osteoblast that is spindle shaped with basophilic cytoplasm dueo to extensive RER and round or oval nuclei

Answer 54

inactive

Question 55

osteoblast that is cuboidal and polarized so that their round and oval nuclei are displaced to the cytoplasm away from the bone they are working on

Answer 55

active

Question 56

osteoblasts are located in the

Answer 56

periphery of bone trabeculae or bone spindles

Question 57

when the matrix is mineralized, the osteoblasts trapped in the matrix differentiates into osteocytes to enter ____

Answer 57

maintenance mode

Question 58

these bone cells are the same cells in 2 separate physiologic state

Answer 58

osteoblast and osteoclast

Question 59

bone cells that have stopped secreting the bone matrix or have significantly reduced secretory function

Answer 59

osteocyte

Question 60

these cells are derived from the osteoblasts that have been trapped in lacunae durimg mineralization

Answer 60

osteocytes

Question 61

round or oval cells with round or oval nuclei and cytoplasmic processes

Answer 61

osteocyte

Question 62

may fused to form osteoclast

Answer 62

osteocyet

Question 63

capable of removing bone matrix through osteolysis

Answer 63

osteocyte

Question 64

maintains the integrity of bone by supplying nutrients from blood vessels

Answer 64

osteocyte

Question 65

these bone cells are derive dfrom the same line as the monocytes

Answer 65

osteoclast

Question 66

large multinucleated cells fromed by the fusion of monocyte precursors

Answer 66

osteoclats

Question 67

what is the reason for the brush border on the side of the adjacent to thebone surface in osteoclast

Answer 67

to increase surface area for resorption

Question 68

its foamy acidophilic cytoplasm is due to the

Answer 68

abundant lysosomes and mitochondria

Question 68

its nuclei are displaced towards the cell border away from the bone edge

Answer 68

osteoclast

Question 68

osteoclast is located on the

Answer 68

concavities on the bone surface calles resorption lacunae (howship's)

Question 69

osteoclast resorb bone by

Answer 69

releasing lysosomal contents n bone surface to digest collagen fibers and hydrogen ions to dissolved mineralized matrix

Question 70

osteoclasts may be mistaken for

Answer 70

megakaryotes

Question 71

Histologically, bone tissue can be divided into two types

Answer 71

woven bone and lamellar bon

Question 72

type of bone accdg to density

Answer 72

cancellous or spongy and compact bone

Question 73

type of bone accdg to manner of evelopmemt

Answer 73

intramembranous and endochondral ossification

Question 74

forms the cylinder surrounding the hematopoietic cavity of long bones

Answer 74

compact bone

Question 75

Develops from cancellous bone by additional deposition of bone substance into existing trabeculae to form layers called lamellae

Answer 75

compact bone

Question 76

a network of anastomosing, angular bone trabeculae separated by interosseous spaces

Answer 76

cancellous or spongy bone

Question 77

spaces between bone trabeculae lined by endosteum and filled with myeloid tissue

Answer 77

interosseous space

Question 78

an islet of bone atrix

Answer 78

bone trabecula or bone spicule

Question 79

have osteocytes within lacunae

Answer 79

trabecula

Question 80

do osteons form

Answer 80

no

Question 81

since trabecula are quite thin, the osteocytes are nourished by

Answer 81

diffusion from bone marrow via the canaliculi

Question 82

found in diaphysis of young tubular bone and in flat bones of mature skull

Answer 82

cancellous or spongy bone

Question 83

this may be developed further into compact bone

Answer 83

cancellous bone

Question 84

how do compact bone develops from cancellous bone

Answer 84

by additional deposition of bone substance into existing trabeculae to form layers called lamellae

Question 85

compact bone presents the ff: lamellae

Answer 85

concentric, interstitial, outer circumferential, inner circumferential

Question 86

compact bone is made up of

Answer 86

osteon

Question 87

the basic structural unit of compact bone

Answer 87

osteon

Question 88

these are circular layers of bone substance that surrounds the osteonal canal and constitute the osteon

Answer 88

concentric lamellae

Question 89

irregular lamellae of bone that filll the spaces between osteons

Answer 89

interstitial lamellae

Question 90

remnants of old osteons varying in size and shape depending on how old they are and how many new osteons have been organized around them

Answer 90

interstitial lamellae

Question 91

what makes it possible to a ge a bone

Answer 91

the proportion of osteons to interstital system is predictable with increasing age

Question 92

circular layers of bone substance that encircle the outer perimeter of bone beneath the periosteum

Answer 92

outer circumferential lamellae

Question 93

circular layers of bone substance that form the wall of the marrow cavity

Answer 93

inner circumferential lamellae

Question 94

a cylinder composed of 4-20 concentric lamellae arranged around a central opening

Answer 94

osteont

Question 95

the central opening in the osteon

Answer 95

osteonal (haversian) canal

Question 96

the formation of bone directly from or within fibrous connective tissue membranes

Answer 96

intramembranous ossification

Question 97

the formation of bone from hyaline cartilage models

Answer 97

endochodrial ossification

Question 98

2 ways of repairing fractued bone

Answer 98

primary and secondary intention healing

Question 99

type of healing bone without formation of external callus

Answer 99

primary

Question 100

healing of bone with formation of external callus during therepair process

Answer 100

secondary

Question 101

stages of bone healing

Answer 101

impact induction inflammatory reparative remodeling

Question 102

manifested by bone injury or trauma

Answer 102

impact stage

Question 103

characterized by torn blood vessels, hemorrhage followed by clot formation and death of bone

Answer 103

impact stage

Question 104

proliferation of osteogenic cells in the inner layer of the periosteum to form a cellular collar near each bone fragment in the area of the fracture

Answer 104

induction stage

Question 105

presence ofr redness, pain, swelling and heat in the area of fracture

Answer 105

inflammatory

Question 106

removal of damage or dead bone tissue and blood clot by inflammatory cells that have migrated to the site of fracture

Answer 106

inflammatory

Question 107

bonding of the newly formed bone to the dead and live bone

Answer 107

remodeling stage

Question 108

replacement of hyaline cartilage by bone and eventual return to normal of the fracture portion of the

Answer 108

remodeling stage

Question 109

migration of collars of osteogenic cells and capillaries from the periosteum and endosteum to the fracture

Answer 109

reparative stage