Exam 5 Mfm Bone Development

Front 1

what are the 2 mechanisms in which bone grows by?

Back 1

intramembranous ossification
endochondral ossification

Front 2

intramembranous ossification = ... ossification (occurs in ... of skin)
ex. bones of skull

Back 2

dermal
dermis

Front 3

endochondral ossification: a ... model that is converted into bone. (growth from ...)

Back 3

hyaline cartilage
cartilage

Front 4

cartilage does not change into bone. It is ... by bone

Back 4

replaced

Front 5

intramembranous bone formation:

This type of bone formation occurs in the ... bones of the skull and face.

Back 5

flat

Front 6

Intramembranous bone formation:

A. ... cells and their fibers constitute a richly vascularized embryonic membrane in which bone develops.

B. Clusters of mesenchymal cells will round up and ... into osteoblasts.
-Osteoblasts become enclosed in purely organic matrix (...).
-When the intercellular matrix becomes impregnated with inorganic salts (calcium phosphates, etc.), the tissue is called ... tissue.

C. As successive layers (...) of bone are laid down on the embryonic membrane, the bony tissue takes the form of ... (network) which form ... (spongy) bone.

Back 6

Mesenchymal
differentiate
osteoid
osseous
lamellae
trabeculae
cancellous

Front 7

intramembranous bone formation:

The intertrabecular spaces become the ... cavities as the mesenchymal cells in these regions differentiate into ... connective tissue and blood-forming cells.

Back 7

marrow
reticular

Front 8

intramembranous bone formation:

D. Bone becomes compact at ... (inner and outer surfaces of bone).

Mesenchymal condensation differentiates into ....

Back 8

periphery
periosteum

Front 9

intramembranous bone formation:

E. ...make their appearance on the inner surfaces of trabeculae and the inner and outer tables of the compact bone.

Back 9

Osteoclasts

Front 10

endochondral bone formation:

Most of the bones of the body are first laid down as ... models.

occurs in all long bones of the body

Back 10

cartilaginous

Front 11

The ends of the bones in an infant contain a large amount of ... cartilage, that later are replaced by bone.

Back 11

hyaline

Front 12

endochondral bone formation:

Chondrocytes in the center of the long bone shafts (diaphysis) hypertrophy and produce alkaline phosphatase leading to ... of the surrounding cartilaginous matrix.

This inhibits diffusion of nutrients to the ... which , therefore, die.


(When blood vessels start coming into cartilage, they start to lay down ..., and bone forms.)

Back 12

calcification
chondrocytes
calcium phosphate

Front 13

endochondral bone formation:

At the same time, the ... chondrogenic layer of the perichondrium becomes increasingly vascularized

This leads to the differentiation of the mesenchymal cells in the perichondrium into ... instead of ..., thus, forming a new periosteum.

These osteoblasts lay down a bony collar around the shaft of the cartilage model.

Back 13

avascular
osteoblasts
chondrocytes

Front 14

endochondral bone formation:

Osteogenic tissue and blood vessels from this osteogenic layer of the ... pass between the trabeculae of the ... and penetrate into the degenerating calcified cartilage.

Small calcified cartilage ... between the lacunae are resorbed and ... tissue is laid down by osteoblasts on remnants of the calcified cartilage.

Back 14

periosteum
bony collar
spicules
osteoid

Front 15

endochondral bone formation:

... start wearing away at the calcified cartilage model.

... will come in and start laying down new ... (bony matrix) on the former calcified cartilage. Uses calcified cartilage as scaffolding

Whole ... area becomes replaced.

Back 15

Osteoclasts
Osteoblasts
osteoid
central

Front 16

endochondral bone formation:

The center of the shaft now consists of osteogenic tissue and bony ... which contain remnant cores of calcified cartilage.

This area within the diaphysis is called the ....

Back 16

trabeculae
primary ossification center

Front 17

endochondral bone formation:

Since the newer cartilage of the original model lies toward the ends of the bone (...), a gradient in the formation and maturation of chondrocytes is seen between the diaphysis and epiphysis (or metaphysis).

Back 17

epiphysis

Front 18

endochondral bone formation:

In this circumscribed region, from the epiphyseal junction toward the primary
ossification center, is found
in succession:

(1)a layer of non dividing cells (...);

(2) ... - where chondrocytes are mitotically and interstitially in an axial orientation

(3) ... and maturation where chondrocytes and lacunae are enlarging;

(4) ... - where intercellular material is calcifying and chondrocytes are dying;

(5) ... - where osteoid is laid down on the calcified cartilage remnants.

Back 18

zone of resting cartilage
zone of proliferation
zone of hypertrophy
zone of calcification
zone of ossification

Front 19

endochondral bone formation:

The multiplication of cartilage cells at each metaphyseal region will result in ... of the shaft of the bone.

Secondary ossification centers develop late in fetal life, or after ..., in the epiphysis.

Neither a periosteum nor a perichondrium is present on articular surfaces which is composed of hyaline cartilage.

Back 19

growth
birth

Front 20

remodeling of bone:

Bone resorption is taking place on some surfaces of the dense and ... bone, while new bone tissue is being laid down on other surfaces.

Back 20

trabecular

Front 21

remodeling of a bone:

In the formation of an osteon, osteogenic material lays down concentric lamellas in a relatively large tunnel until only a small ... is formed.

What happens during remodeling of compact bone. Bone can respond by forming a unit around blood vessels.

Back 21

Haversian canal

Front 22

remodeling of bone:

If there is a need for calcium elsewhere in the body, or if there is a change in the direction or strength of forces acting on the bone, ... of some Haversian systems, or parts of the systems will take place.

Back 22

resorption

Front 23

repair of a bone fracture:

When bone is fractured, blood vessels of Haversian systems and periosteum are damaged in the area of the break.

... die in the general vicinity of the break where a ... also forms.

This is followed by the formation of ... tissue (new blood vessels surrounded by macrophages).

Osteogenic cells of undamaged periosteum and endosteum proliferate and invade the damaged area to form a callus in the marrow cavity (...) and one that surrounds the apposed broken ends of the bone (...).

Back 23

Osteocytes
blood clot
granulation
internal callus
external callus

Front 24

repair of bone fracture:

If the regeneration of the vasculature keeps pace with the laying down of osteogenic cells, the callus will be of ... tissue.

If the vascularity is slower to regenerate, the callus will form as ...

Often the callus will initially have an outer ... covering and an inner ... core; the latter replaced by ... as the vasculature proliferates and repairs.

Back 24

bone
cartilage
bony
cartilaginous
bone

Front 25

repair of bone fracture:

The dead bone near the fracture line is resorbed and replaced by new bone. ... bone is formed between the broken ends which eventually is remodeled into ... bone.

The ... bone of the internal and external callus are resorbed.

Back 25

Cancellous
compact

trabecular