Bone Formation and Development Flashcards
Adult bones are composed of __ percent protein (called____),____ percent minerals (including___,___,and____), and ____ percent___.
30 ; ossein
45
calcium, phosphorus, and magnesium
25
water
Minerals give the bone____ and_____.
strength
hardness
At birth, bones are(soft or hard?) and ____ because of _____ in their structure.
Soft
pliable
cartilage
As the body grows, (younger or older?) cartilage gradually is replaced by _______
Older
hard bone tissue.
Minerals in the bones (increase or decrease?) with age, causing the bones to become more ____ and____
Increase
brittle
easily fractured.
EMBRYOLOGY of bone
-In the early stages of embryonic development, the embryo’s skeleton consists of ____ membranes and____ cartilage.
fibrous
hyaline
By the ____ or ____ week of embryonic life, the actual process of bone development,ossification(______), begins.
sixth
seventh
osteogenesis
There are two osteogenic pathways:____ ossification and______ ossification
intramembranous
endochondral
Mature bones differ from one another based on the process of osteogenesis that made it
T/F
F
in the end, mature bone is the same regardless of the pathway that produces it.
Intramembranous Ossification of bone
-Duringintramembranous ossification, _____ and _____bone develops directly from_______(differentiated or undifferentiated?) connective tissue.
compact and spongy
sheets of mesenchymal
undifferentiated
The ___ bones of the____, most of the_____ bones, and the ______ are formed via intramembranous ossification.
flat; face
Cranial
clavicles (collarbones)
The process of intramembraneous ossification begins when mesenchymal cells in the embryonic skeleton ______and begin to_____
-Some of these cells will differentiate into____, while others will become _____ (_____) cells and then ______.
gather together
differentiate into specialized cells
capillaries
osteogenic; bone producing
osteoblasts
Although clusters of osteoblasts will ultimately be spread out by the______, early osteoblasts appear in a cluster called an_____.
formation of bone tissue
ossification center
Intramembranous ossification beginsin _____during fetal development and continues on into _____.
utero
adolescence
-At birth, the ____ and ____are not fully ossified nor are the_____(____) closed.
And This allows the ____ and____ to deform during passage through the birth canal.
skull and clavicles
junctions between the skull bone
Sutures
skull and shoulders
The last bones to ossify via intramembranous ossification are the ______, which reach their adult size at the ____ of the _____
flat bones of the face
end
adolescent growth spurt
Endochondral Ossification
-Inendochondral ossification, bone develops by______
replacinghyaline cartilage.
Cartilage becomes bone.
T/F
F
Cartilage does not become bone.
cartilage serves as a ____ to be_____ by new bone.
template
completely replaced
Which takes longer, intramembranous ossification or Endochondral ossification?
Endochondral ossification takes much longer than intramembranous ossification.
Bones at the base of the skull form via _____ ossification.
endochondral
long bones form via _____ ossification.
endochondral
In a long bone, for example, at about __to__ weeks after conception, some of the mesenchymal cells differentiate into____ (____cells) that form the ______skeletal precursor of the bones
6 to 8
chondroblasts
cartilage
hyaline cartilaginous
Hyaline cartilage is a (flexible or rigid?) , (solid or liquid?)matrix produced by _____ and consists of _____,______,_____, and____.
-As the matrix surrounds and isolates_____, they are called ______.
Flexible
Semi-solid
chondroblasts
hyaluronic acid; chondroitin sulfate; collagen fibers; water
chondroblasts; chondrocytes
cartilage is (vascular or avascular?)
Avascular
cartilage is avascular, meaning that it has no blood vessels supplying nutrients and removing metabolic wastes.
-All of these functions are carried on by _____ from vessels in the surrounding_____, a membrane that covers the cartilage
diffusion through the matrix
perichondrium
Growth of Bone
- Long bones continue to lengthen, potentially until _____, through the addition of bone tissue at the ______.
- They also increase in width through _____ growth.
adolescence
epiphyseal plate
appositional
Lengthening of Long Bones
-Chondrocytes on the _____ side of the epiphyseal plate are going to ____; one cell remains undifferentiated near the _____, and one cell moves toward the_____.
epiphyseal
divide
epiphysis
diaphysis
Lengthening of Long Bones
The cells, which are pushed from the _____, mature and are destroyed by_____.
-This process replaces cartilage with bone on the _____ side of the plate, resulting in a lengthening of the bone.
epiphysis
calcification
diaphyseal
Long bones stop growing at around the age of ____ in females and the age of____ in males in a process called _______
- During this process, ____ cells stop dividing and all of the ____ is replaced by____
- The ____ plate fades, leaving a structure called the _____ or _____, and the ____ and ____ fuse.
18
21
epiphyseal plate closure
cartilage; cartilage;bone
epiphyseal
epiphyseal line or epiphyseal remnant
epiphysis and diaphysis
Thickening of Long Bones
- Appositional growthis the increase in the _____ of bones by the addition of bony tissue at the ____ of bones.
- _____at the bone’s___ surface secrete _____, and____ on the____ surface break down bone.
diameter
surface
Osteoblasts; outer ; bone matrix
osteoclasts; inner
In thickening of long bones
The osteoblasts differentiate into______.
osteocytes
A balance between osteoblasts and osteoclasts processes allows the bone to ____ without becoming____.
thicken
too heavy
Bone Remodeling and Repair:
It involves the processes of bone deposition by ___ and bone resorption by _____.
osteoblasts
osteoclasts
Bone renewal continues after birth and stops at adolescence
T/F
F
Reaches adulthood
Bone remodelingis the _____ tissue by ____ tissue.
replacement of old bone
new bone
Normal bone growth requires vitamins __,___,and___ plus minerals such as ___,___,and___
D, C, and A,
calcium, phosphorous, and magnesium.
Hormones such as _____ hormone, ____ hormone, and_____ are also required for proper bone growth and maintenance.
parathyroid
growth
calcitonin
Bone remodeling allows bones to adapt to stresses by becoming____ and____ when subjected to stress.
thicker
stronger
Bones that are not subject to normal stress, for example when a limb is in a cast, will begin to____
lose mass.
A fractured or broken bone undergoes repair through four stages:
(1)Blood vessels in the broken bone____and ____, resulting in the formation of____, or a____, at the site of the break.The severed blood vessels at the broken ends of the bone are sealed by the ___ process, and bone cells that are deprived of nutrients begin to___.
tear and hemorrhage
clotted blood
Hematoma
Clotting
die
A fractured or broken bone undergoes repair through four stages:
(2)Within ___ of the fracture,____ grow into the hematoma, and phagocytic cells begin to ________Though fragments of the blood clot may remain, ____ and ____enter the area and begin to reform bone.Some bone ____ may also appear at this point.
days
capillaries
clear away the dead cells.
fibroblasts and osteoblasts
spicules
Fibroblasts produce ____that_____, and osteoblasts start to———.
collagen fibers
connect the broken bone ends
form spongy bone
The repair tissue between the broken bone ends is called the_____, as it is composed of both _____ and _____
fibrocartilaginous callus
hyaline and fibrocartilage.
A fractured or broken bone undergoes repair through four stages:
(3)The fibrocartilaginous callus is converted into a _____ of ____ bone.It takes about ____for the broken bone ends to be firmly joined together after the fracture.This is similar to the _____ formation of bone, as cartilage becomes ossified; osteoblasts, osteoclasts, and bone matrix are present.
bony callus
spongy
two months
endochondral
A fractured or broken bone undergoes repair through four stages:
(4) The bony callus is then remodelled by___and ___, with excess material on the (interior or exterior?) of the bone and within the ______ being removed.
______bone is added to create bone tissue that is similar to the original, unbroken bone.But note that This remodeling can take ___, and the bone may remain ____ for years.
osteoclasts and osteoblasts
Exterior
medullary cavity
Compact
many months
uneven
Bone turnover rates are quite (high or low?), with ___ to___ percent of bone mass being recycled every ____.
High
Five to seven
week
bone turnover rate are different in different areas of the skeleton but the same in different areas of a bone.
T/F
F
Differences in bone turnover rate exist in different areas of the skeleton and in different areas of a bone.
the bone in the ___ of the femur may be fully replaced every ____ whereas the bone along the ____ is altered much more (slowly or rapidly?)
head
six months,
shaft
Slowly
