BONE BEINARTAS & JURONIS
Double-layered connective tissue membrane that covers the outer surface of a bone
periosteum
This area of bone formation is called a __________________________________.
primary ossification center
What does red morrow in bones do for the body?
produce all blood cells
what are the two types of bone marrow?
red and yellow
Site of Blood Cell Formation
red bone marrow
In addition, the bone becomes weaker because of incomplete bone___________________.
remodeling
Can occur when children have insufficient vitamin D
rickets
Results from vitamin C deficiency in adults or children.
scurvy
What are carpals and tarsals?
short bones
examples of ball and socket joints
shoulder and hip
Intramembranous ossification produces many bones of the....?
skull
What are the bones of the axial skeleton?
spinal column, skull, rib cage
Which bone tissue is found more on the inside (interior) of bone and very poreous (lots of holes)?
spongy
During aging Trabecular bone loss is greatest in the trabeculae that are under the least _____________________
stress
What attaches muscles to bones?
tendons
Male sex hormone that encourages large amount of bone growth.
testosterone
In cancellous bone, the BMU removes bone matrix from the surface of a(n) _________________________ forming a cavity, which is then filled in by the BMU with new bone matrix.
trabecula
Osteons are to compact bone as ___ are to spongy bone.
trabeculae
Bone that forms through intramembranous ossification starts as
undifferentiated mesenchymal tissue
Necessary for normal collagen synthesis by osteoblasts.
vitamin c
Apposistional growth beneath the peristuem is responsible for the increased ______of long bones.
width
Adipose Tissue in Medullary Cavity of Long bones
yellow bone marrow
hypertrophied chondrocytes are surrounded by calcium carbonate and eventually die in the _________
zone of calcification
chondrocytes produced in the zone of proliferation mature and enlarge in the ________
zone of hypertrophy
chondrocytes in the _____ divide rapidly / produce new cartilage
zone of proliferation
in the epiphyseal plate randomly arranged chondrocytes nearest the epiphysis are in the ___
zone of resting cartilage
Osteoclasts
Large cell with several nuclei; responsible for the resorption (breakdown) of mineralized bone matrix.
Bone to bone
Ligaments attach _____ to _____
Collagen and Proteoglycans
Major organic component of bone; lends flexible strength to bones.
Chondrocyte
Mature cartilage cell, in a lacuna that is surrounded by matrix.
Large internal space within the diaphysis
Medulary Cavity
Stem cells
Mesenchymal cells that give rise to more specialized cell types
Osteocytes
Osteoblast that has become surrounded by bone matrix.
When chondrocytes in this calcified area die, blood vessels grow into the enlarged lacunae and bring in ____________, which produce bone trabeculae.
Osteoblasts
_________ cells become osteoblasts and produce tiny trabeculae of woven bone.
Osteochondral progenitor cells
At the same time,___________________ remove bone from the diaphysis to produce the medullary cavity.
Osteoclasts
If the blood Ca level decreases, the secretion of PTH increases, resulting in increased numbers of ________________.
Osteoclasts
______________, from the parathyroid glands is the major regulator of blood Ca2+ levels.
Parathriod cells
Collagen fibers that penetrate the Periosteum and outer parts of the bone
Perforating Sharpey´s Fibers
Hydroxyapatite
Primary mineral in bone; gives bone matrix compression (weight-bearing) strength.
This area of bone formation is called a __________________________________.
Primary ossification center
Ruffled border
Projections from the plasma membrane of an osteoclast where it contacts bone matrix.
Canaliculi
Spaces occupied by osteocyte cell bodies.
Lacunae
Spaces occupied by osteocyte cell bodies.
Ligament
Strong band of fibrous connective tissue that attaches bone to bone; allows movement but prevents excessive movement.
Tendon
Strong band of fibrous connective tissue that attaches muscle to bone.
Osteoblasts
The cell type that is responsible for maintaining bone once it has been formed is the
Hydroxyapatite crystals
The compression (weight-bearing) strength of bone matrix is due to the presence of
What the function of bones of the axial compare to bones of the appendicular skeleton?
Appendicular gives movement with muscles while axial give protection of organs.
Hyaline Cartilage that covers the end of a long bone
Articular Cartilage
The osteoblasts produce compact bone on the surface of the cartilage model, forming a____________.
Bone collar
Chondrocytes in the center of the cartilage model hypertrophy, or enlarge, and the matrix between the enlarged cells becomes mineralized to form ____________________.
Calcified cartilage
Small channels extending through the bone matrix are...?
Canaliculi
Appositional growth
Cartilage growth that occurs when chondroblasts in the perichondrium lay down new matrix and add chondrocytes to the outside of the tissue.
Interstitial growth
Cartilage growth that occurs when chondrocytes within the tissue divide and add more matrix between the cells.
Osteoblasts
Cell that produces mineralized bone matrix but is not surrounded by matrix.
Chondroblast
Cell that produces new matrix on the outside of cartilage.
Osteochondral progenitor cells
Cells that have the ability to become osteoblasts or chondroblasts.
Cartilage matrix
Chondroblasts produce
Bone matrix
Collagen and calcium hydroxyapatite are the primary constituents of
In which type of bone would osteons be present?
Compact bone
Bone
Contains marrow that gives rise to blood cells and platelets.
Articular cartilage
Covers the ends of bones where they come together to form joints.
Lay down bone matrix
The primary function of osteoblasts is to...
If blood Ca2+ levels are too high, osteoclast activity _________________, which results in a net movement of Ca2+ from blood to bone.
Decreases
If the blood Ca level ___________, the secretion of PTH increases,
Decreases
Perichondrium
Double-layered connective tissue sheath around cartilage.
Hyaline cartilage
The type of cartilage associated with bone function and development is...
Cartilage
Tissue that provides flexible support and forms a smooth surface at some joints.
Bone
Tissue that stores minerals and fat.
Interconnecting rods of bone are...?
Trabeculae
True or False: Bones make our blood?
True
Ture or False: Compared to spongy bone, compact bone is found more superficial?
True
Hyaline Cartiage between Diaphysis and Epiphysis; growth in length of the bone occurs here
Epiphyseal Plate
End of a long bone; composed of cancellous bones, with an outer layer of compact bone
Epiphysis
Secondary ossification centers appear in the ________________________________ about 1 month before birth.
Epiphysis
True or False: Bone is dead tissue our body uses for support.
False
True or False: Bone marrow is found inside the trabeculae of spongy bone?
False
Ossification (osteogenesis)
Formation of bone by osteoblasts.
Protection and brain and soft organs
Important functions of the skeletal system include
When blood Ca2+ levels are too low, osteoclast activity _______________________ and more Ca2+ are released into the blood.
Increases
Why is bone considered alive?
It has a blood supply; It grows
Adults don't grow much so they don't need to make tons of blood cells like kids. Who has more red marrow?
Kids
Bone
Very rigid tissue that bears weight and supports the body, protects internal organs, and provides attachment for muscles to produce body movement.
Necessary for the normal absorption of calcium from the intestines.
Vitamin D
Osteoclasts
Which of the following cell types is responsible for breaking down bone matrix?
Immunity
Which of the following is NOT a function of bone?
Osteoclasts
Which type of bone cells are large cells that form from fusion of monocytes?
Osteochondral progenitor cells (OPCs)
Which type of bone cells give rise to osteoblasts?
Bone growth can only occur by...?
appositional growth
osteoblasts deposit bone matrix through _________ to produce new bone matrix which is later _________
appositional growth remodeled
Haversian systems or osteons...
are the basic units in compact bone tissue
A(n) ______________________ is a temporary assembly of osteoclasts and osteoblasts that travels through or across the surface of bone, removing old bone matrix and replacing it with' new bone matrix.
basic multicellular unit
The osteoblasts produce compact bone on the surface of the cartilage model, forming a____________.
bone collar
Chemical most present in bones
calcium
Chondrocytes in the center of the cartilage model hypertrophy, or enlarge, and the matrix between the enlarged cells becomes mineralized to form ____________________.
callcified cartilage
Osteons are the basic unit to compact bone. Which of the following can be found in an osteon? Choose all.
canaliculi, matrix, osteocyte
A slow loss of ______________ bone begins about 40 and increases after age 45.
cancellous
Cartilage in the internal and external calluses is replaced by woven,_____________________ bone.
cancellous
In which type of bone would trabeculae be present?
cancellous bone
These locations of bone formation are called _______________
center of ossification
Osteochondral progenitor cells from the periosteum become ____________________ which produce cartilage.
chondroblasts
The bone matrix in an older bone is more brittle than a younger bone because decreased ________________ production results in a matrix that has relatively more mineral and less collagen fibers.
collagen
Woven bone is ...
collagen fibers randomly oriented
Finally, woven bone is remodeled to form ____________________ bone, in which osteons extend across the fracture line to "peg" the bone fragments together.
compact
Which bone tissue is found more on the circumference of bone and very dense?
compact
What are the two types of bone tissue?
compact and spongy
What is found just deep to the periosteum?
compact bone
Cancellous bone tissue ...
contains interconnecting plates called trabeculae
Calcitonin, secreted from the thyroid gland, ______________ osteoclast activity.
decreases
PTH _______________ the Ca2+ lost in the urine.
decreases
When PTH secretion increases, OPG secretion ________________, resulting in less inhibition of osteoclast precursor cells, as well as more osteoclasts.
decreases
Shaft of a long bone; primarily of compact bone
diaphysis
primary ossification occurs in the ______ and secondary ossification occurs in the ________
diaphysis ; epiphysis
Something with an ____________ can support greater weight, which means they can grow bigger
endo(skeleton)
What are the 2 basic types of skeletons?
endoskeleton and exoskeleton
Bones become thinner, but their outer dimensions change little, because most loss of compact bone occurs under the __________ on the inner surface of bone.
endosteum
Single Layer of Cells that lines the internal surfaces of all cavities within the bone, including the Medulary cavity
endosteum
growth occurs in articular cartilage and responsible for the growth of the ________
epiphysis
The ends of long bone is called ______ while the middle is called _______.
epiphysis; diaphysis
Sex hormone that causes the earliest closure of the epiphyseal plate.
estrogen
Something that has an ____________ can quickly outgrow its skeleton and must molt
exo(skeleton)
Where do we find spongy bone?
facing the medullary/marrow cavity, lining the inside of a diaphysis, making up most of the inside of an epiphysis
Yellow marrow is mostly?
fat and lipids
Bone tissue adjacent to the fracture site dies. Blood vessels grow into the clot produced by the hematoma. When the clot dissolves, _________________ produce a fibrous network.
fibroblasts
Some skull bones, ribs, sternum, and scapula
flat bones
intramembranous ossification is a process which leads to the formation of
flat bones
At birth, some membrane is not ossified and these regions are called_________________.
fontanels
Endochondral ossification having 2 ossification centers allows for
formation of an epiphyseal plate
Significant loss of bone increases the likelihood of bone ______________________.
fracture
Increase general tissue growth
growth hormone and thyroid hormone
When bone is fractured, blood vessels in the periosteum and in the bone bleed, and a(n)_________________________ is formed.
hematoma
In endochondral ossification begins withIn endochondral ossification begins with
hyaline cartilage
The first phase of endochondral ossification is the formation of a ______________________ model by chondroblasts, which become chondrocytes when they are surrounded by cartilage matrix.
hyaline cartilage
PTH ____________ Ca2+ uptake in the small intestine,
increases
PTH ______________ the reabsorption of Ca2+ from the urine,
increases
PTH ___________________ the formation of vitamin D in the kidneys,
increases
Chondroblasts and Osteoblasts form a bone and cartilage collar, called a(n)_______________ around opposing ends of the bone fragments.
internall callus
Chondroblasts invade the fibrous network and form a(n)________________________, which is located between the ends of the broken bone.
internall callus
Portions of older osteons, called _____________________ are left between the newly developed osteons.
interstitial lamellae
vertebrae?
irregular bone
vertebrae, facial bones
irregular bones
How does the Skeletal System use the hematopoiesis to support the body?
it creates blood cells
What is homeostasis?
keeping the body steady state during changes
The spaces in osteons called ______ hold mature bone cells called ______
lacunae, osteocyte
growth of the epiphyseal plate is responsible for the increase in ________ of long bones
length
What attaches bones together?
ligaments
what are limb bones?
long bones
what does the axial skeleton protect?
lungs and brain
Remodeling occurs constantly in bones. For example, as long bones increase in length and diameter, the size of the ______________________ also increases.
medullar cavity
Where is yellow marrow found?
medullary cavity
What do ball and socket joints guarantee?
movement
Lamellar bone is ...
organized into thin sheets of tissue
This bone cell builds bone : ____________; while this bone cell destroys bone: _____________.
osteoblast; osteoclast
Mechanical stress increases the activity of ____________________________________.
osteoblasts
Osteochondral progenitor cells from the periosteum become _______________, which form bone,
osteoblasts
Pressure in bone causes an electric change that increases the activity of ________________________________ and speeds the healing of broken bones.
osteoblasts
When chondrocytes in this calcified area die, blood vessels grow into the enlarged lacunae and bring in ____________, which produce bone trabeculae.
osteoblasts
When blood vessels invade the perichondrium surrounding the cartilage, ___________________ cells within the perichondrium become osteoblasts.
osteochondral progenitor
When blood vessels invade the perichondrium surrounding the cartilage, ___________________ cells within the perichondrium become osteoblasts.
osteochondral progentior
When osteocytes realize that there is a bone fracture it triggers ______ to first break down calcium which then leads to _____ cells that build new bone.
osteoclast;osteoblast
At the same time,___________________ remove bone from the diaphysis to produce the medullary cavity.
osteoclasts
Increased PTH promotes an increase in osteoclast numbers by increasing receptor for activation of nuclear factor kappa B ligand (RANKL) production on the surface of _____________ and stromal (stem) cells.
osteoclasts precurser cells
RANKL binds to receptor for activation of nuclear factor kappaB ligand (RANK) on the surface of __________________ and stimulates them to become osteoclasts
osteoclasts precurser cells
Softening of the bones because of calcium depletion in adults.
osteomalacia
removing old bone matrix and replacing it with' new bone matrix produces new __________________ in compact bone.
osteons
_______________, which is also secreted from osteoblasts and stromal cells, inhibits osteoclast production.
osteoprotegerin
Tendon
A band of connective tissue that attaches a muscle to a bone is a(n)
how many bones are in the adult human body?
206
How many different sockets are there for bones to connect to?
5