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Chapter6

BonesandSkeletalTissues

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The

Skeletal

System

___________

+

___________

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Reviewof

Cartilage

Basics

CartilageisCT

Abundantextracellularmatrix

Gellike

Somefibers

Predominantcell

type

=__________________

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HyalineCartilage

Chondrocyteswithinlacunae

Collagen__________withinmatrixunseen

Locations:

Endsoflongbones

Growthplateswithinbones

Costalcartilages

Respiratorystructures

Embryonicskeleton

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ElasticCartilage

Chondrocyteswithin

lacunae

Elasticfibersin

matrixhighlyvisible

Locations:

Epiglottis

Outerear

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Fibrocartilage Intermediatebetweenhyaline

cartilageanddenseregularCT

Rowsof________chondrocytes

Rowsofcollagenfibersinparallel

Locations:

Intervertebraldiscs

Articularcartilages

in

the

knee

menisci

Pubicsymphysis

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Functions

of

Bones Support:frameworkofthebody

Protection:bonesandcartilagedothis(e.g.,_____________)

Movement:attachment

sites

for

skeletal

muscles

Mineralstorage:__________________________________

Hemopoiesis:bloodcellformationredbonemarrow

_______________________:yellowbonemarrow

Metabolism:regulation

of

insulin

and

fat

storage

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ClassificationofBones

LongbonesLongerthantheyarewide

Shaft+two

distinct

ends

Namedforshape,notsize

ShortbonesRoughlycubeshaped

Carpals/Tarsals

Sesamoidbones(form

withintendons)

FlatbonesThin,flattened,curved

Cranialbones,

ribs,

sternum,scapula

IrregularbonesVariousshapes

Vertebrae,Os Coxae

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Compact&

Spongy

Bone

Dense,outerlayeris

compactbonetissue

Internallyyoufind

spongybonetissue(aka:

____________bone)

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GrossAnatomyofaLongBone

Metaphysis=

____________

where

diaphysisjoins

epiphysis

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Define

these

terms!!! Diaphysis

Epiphysis

Metaphysis regionwherediaphysismeetsepiphysis

Epiphyseal

Plate

EpiphysealLine

ArticularCartilage hyalinecartilageattheendsofarticulatingbones

MedullaryCavity

NutrientForamen

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BoneMembranes

__________________

Surrounds

the

external

bone

surface

where

it

is

notcoveredby

articular

cartilage

Twolayers: Superficiallayer=_________________________

Deeplayer

=

_______________Osteoblasts depositbonetissue

Osteoclasts destroybonetissue

SharpeysFibers Perforatingfibersoftheperiosteumdiveintothebonematrix

tosecure

it

to

the

bone

Atinsertionpointsofmusclestobone,theseperforatingfibersareverydense

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BoneMembranes

_______________

Thinmembrane

that

linestheinternalbonesurface

Coversthetrabeculaeof

spongy

bone

Medullarycavity

Epiphyses

Osteogenic

(osteoblastsandosteoclastspresent)

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GrossAnatomyofShort,Irregular&

FlatBones

Periosteum

Endosteum

(coveringtrabeculae)

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MicroscopicAnatomyofCompactBone

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Haversian

System

=

OsteonAnosteonisthe

organized

unit

of

compactbonetissue.

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Haversian

System

A

Closer

Look

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Define

these

terms!!! Osteon

Lamella

CentralCanal

PerforatingCanal

Osteocyte

Lacunae

Canaliculi

InterstitialLamellae

CircumferentialLamellae

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MicroscopicAnatomy

of

Spongy

Bone

Trabecula=littlebeam

Eachtrabeculaissolid

Nocavitiesorvessels

inside Receivenutrientsfrom

surrounding_________________

________bonemarrowfoundinthespaces

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ChemicalComposition

of

Bone

Organiccomponents:_________

Collagen

fibers

Cells

Groundsubstance

Inorganiccomponents:_________

Mineralsalts

Tightlypacked

calcium

and

phosphate

crystals

cover

the

longcollagenfibers

Hardnessofbone

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BoneDevelopment

Theprocessbywhichboneformsiscalled

___________________or________________

Bone

formation

occurs

in

four

situations:1. Formationofboneinanembryo

2. Growthofbonesuntiladulthood

3. Remodelingof

bone

throughout

life

4. Repairoffractures

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Ossification

Boneformationfollowsoneoftwopatterns:

_________________________ossification

Boneformsdirectlywithinmesenchymearrangedin

layersthatresemblemembranes

Mostskull

bones

and

the

clavicles

_________________________ossification

Boneformswithinhyalinecartilage,replacingit All

bones

from

base

of

skull

down

(except

clavicles)

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EndochondralOssification

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Howdo

bones

get

LONGER?

Thelengtheningofbones

involvestwo

steps:

1. Cartilagegrowthonthe__________________oftheepiphysealplate

2. Replacement

of

cartilage

by

boneonthe_____________

Atadulthood,theepiphyseal

platesclose

and

bone

replacesallthecartilageleavingabonystructurecalledthe_______________

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Howdo

bones

get

THICKER?

____________________growth:

Ostseoblasts

in

the

periosteum

add

bone

tissue

to

theexternalbonesurface

Osteoclastsremovebonetissuefromthe

medullary

cavity

at

the

same

rate

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BoneRemodeling

Oldboneiscontinuallydestroyedandnewboneisformedinitsplacethroughoutanindividualslife Spongy

bone

is

replaced

about

every

_________________

Compactboneisreplacedaboutevery_________________

A

balance

must

exist

between

the

actions

of

osteoclasts

andosteoblasts Toomuchbonedepositionresultsinabnormalthickening,

lengthening,anddensityofbones

Too

little

bone

deposition

results

in

fragile

bones

that

fracturetooeasily

Remodelingrate:Diaphysisvs.Epiphyses

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Osteoblast

vs.

Osteoclast BoneDeposition________________

Occurswhenboneisinjuredoraddeddemandis

placedon

the

bone

Essentialionsmustbepresent

Mineralsaltcrystalspacktogetherinapatternthatreducestheriskofcracksinstressedbone

BoneResorption_______________OsteoclastssecreteHClandlysosomalenzymes

Asorganic

matrix

is

degraded

and

the

mineral

salts

areleachedoutanddissolvedbytheacids,thereleasedionsenterinterstitialfluidandthentheblood