bone and ossification histo

Question 1

makes up the greater portion of the matrix

Answer 1

Inorganic elements – calcium, magnesium, and sodium

Question 2

Ground substance is calcified – becomes hard and brittle

Answer 2

bone

Question 3

organic elements of bone

Answer 3

(collagen, protein polysaccharide and chondroitin sulfate)

Question 4

functions of bone

Answer 4

Internal support of the body
Attachment of muscles and tendons for locomotion
Contains the bone marrows – blood forming elements
Protects vital organs of the cranial and thoracic cavities
For storage of calcium in the body

Question 5

types of bone based on the organization of its type I collagen fibers

Answer 5

lamellar

woven

Question 6

type of bone
collagen fibers are arranged in an irregular feltwork
fabricated during periods of rapid bone growth

Answer 6

woven

Question 7

type of bone
hypercellular, with large osteocytes and lacunae, distributed in a haphazard fashion, long axes follow the direction of the neighboring collagen fibers

Answer 7

woven

Question 8

type of bone

higher mineral content than that of lamellar bone; deposited outside of collagen fibers

Answer 8

woven

Question 9

type of bone

resist forces equally in all directions; weaker, less rigid, more flexible than lamellar bone (greenstick fracture)

Answer 9

woven

Question 10

type of bone

collagen fibers are deposited in parallel arrays

Answer 10

lamellar

Question 11

type of bone
synthesized more slowly, less cellular, smaller osteocytes and lacunae, distributed in a more organized fashion along the more regular collagen lamellae

Answer 11

lamellar

Question 12

type of bone

process of mineralization occurs more slowly and continues long after the organic matrix is initially deposited

Answer 12

lamellar

Question 13

type of bone

has greater rigidity and tensile strength, less elasticity than woven bone.

Answer 13

lamellar

Question 14

FORMS OF LAMELLAR BONES

Answer 14

Cancellous or Spongy bone (substancia spongiosa)

Compact bone (substancia compacta)

Question 15

LONG BONE

– thick walled hollow cylinder w/ a central medullary cavity containing the bone marrow

Answer 15

Shaft

Question 16

LONG BONE

ends of long bones made up of spongy bone covered by a thin cortex of compact bone

Answer 16

Epiphysis –

Question 17

LONG BONE

– separates the epiphysis from the diaphysis

Answer 17

Epiphyseal plate

Question 18

LONG BONE

a transitional region connecting the epiphyseal plate to the diaphysis

Answer 18

Metaphysis

Question 19

long bone

a layer of specialized CT w/ osteogenic potential

Answer 19

Periosteum

Question 20

long bone

a thin cellular layer w/ osteogenic properties covering the marrow cavity

Answer 20

Endosteum

Question 21

Found in the flat bones of the face and skull

Layer of spongy bone between 2 layers of compact bone forming an outer and inner table

Answer 21

diploe

Question 22

bone cells

Answer 22

Osteoprogenitor cells

2. Osteoblasts
3. Osteocytes
4. Osteoclasts

Question 23

type of bone cells
Undifferentiated cells

On free bony surfaces,
endosteum, periosteum,
lining of the Haversian
canal, epiphyseal plate

With pale staining
nucleus and faintly
basophilic cytoplasm

Answer 23

Osteoprogenitor cells

Question 24

type of osteoprogenitor cells

Divide – (bone - forming cells)

Answer 24

osteoblasts

Question 25

type of osteoprogenitor cells | Unite – (bone - destroying cells)

Answer 25

osteoclasts

Question 26

Bone forming cells responsible for the development of the bony matrix Location: surfaces of developing bones Arranged in an epitheloid layer of cuboidal cells

Answer 26

osteoblasts

Question 27

Cells of fully formed bones in the lacunae of calcified matrix An osteoblast is surrounded by bone matrix in its development Flattened cell body inside the lacunae

Answer 27

osteocytes

Question 28

Giant multinucleated cells closely associated with areas of resorption Found in shallow concavities of the bone surface called Lacuna of Howship

Answer 28

osteoclasts

Question 29

osteoclasts are found in shallow concavities of the bone surface called

Answer 29

Lacuna of Howship

Question 30

Active in bone resorption Ruffled border – radial striations found close to the bone

Answer 30

osteoclasts

Question 31

Irregular branching bony spicules forming a network of interconnecting spaces containing bone marrow With thin trabeculae made up of irregular lamellae of bone with lacunae containing osteocytes

Answer 31

spongy bone

Question 32

Absence of haversian system Trabeculae lined by endosteum containing osteoprogenitor cells, osteoblasts & osteoclasts

Answer 32

spongy bone

Question 33

Parallel columns made up of concentric bony layers surrounding the haversian canal

Answer 33

Compact bone:

Question 34

haversian channel with the concentric bony lamellae

Answer 34

Haversian system -

Question 35

at right angle to the haversian canal

Answer 35

Volkmann’s channel -

Question 36

numerous minute interconnecting canals

Answer 36

Canaliculi -

Question 37

found between Haversian systems formed as a result of the continuous resorption and redeposition of bone

Answer 37

Interstitial lamellae -

Question 38

– found at the outermost portion of the compact bone that extends around the circumference of the shaft

Answer 38

Periosteal / External Circumferential Lamellae

Question 39

surrounds the central medullary cavity

Answer 39

Endosteal / Inner Circumferential Lamellae –

Question 40

fibrous tissue covering the outersurface of the bone; bound to the underlying bone by Sharpey’s fibers

Answer 40

Periosteum –

Question 41

lines the central medullary cavity

Answer 41

Endosteum –

Question 42

Between lamellae are _________ in lacuna

Answer 42

osteocytes

Question 43

histogenesis of bone

Answer 43

Intramembranous Ossification – occurs directly in primitive CT 2. Intracartilaginous / Endochondral Ossification – replacement of cartilage by bone

Question 44

histogenesis of bone | occurs directly in primitive CT

Answer 44

Intramembranous Ossification –

Question 45

histogenesis of bone replacement of cartilage by bone

Answer 45

2. Intracartilaginous / Endochondral Ossification –

Question 46

when bone arises in tissues not belonging to the skeletal system or in CT w/o osteogenic properties

Answer 46

Ectopic bone formation –

Question 47

Bone formation occurs directly in primitive CT w/o cartilage formation Commonly seen in the flat bones of the face & skull

Answer 47

Intramembranous Ossification

Question 48

Involves the replacement of a cartilage model by bone Cartilage destruction is a pre-requisite Involves the bones of the entire skeletal system except the bones of the face & skull

Answer 48

Intracartilaginous / Endochondral Ossification

Question 49

Occurs later & appears at birth Sequence of changes similar to that in the diaphyses Less bone destruction & no formation of a single marrow cavity What remains is spongy / cancellous bone with a thin plate of compact bone surrounding it

Answer 49

EPIPHYSEAL OSSIFICATION

Question 50

Imbalance between bone resorption and bone formation. Reduced bone mineral density Increased bone fragility & incidence of fracture

Answer 50

OSTEOPOROSIS

Question 51

Blood clot replaced by vascularized granulation tissues Initial formation of provisional callus (hyaline cartilage) from granulation tissues Provisional callus transformed into temporary callus that unites the fractured bone

Answer 51

bone repair

Question 52

Temporary callus is replaced by woven bone leading to a bony union of the fracture Woven bone is transformed into compact bone and excess bone is resorbed.

Answer 52

bone repair

Question 53

Found in the marrow cavity of the diaphysis of long bones Abundant fat cells – yellow color Not active in hemopoiesis

Answer 53

yellow bone marrow