L.6. CONNECTIVE TISSUES.pdf

Connective tissues

1. KILIMANJARO CHRISTIAN MMEDICAL UNIVERSITY
COLLEGE
Faculty of Nursing and Rehabilitation Medicine
Department of Anatomy and Neuroscience
Anatomy Lecture for BSc.Nursingand BSc.Physiotherapy
LECTURE 6
TOPIC: CONNECTIVE TISSUES
Date: Nov. 7
th
2022, from 10:30 am -12:30pm, GYM –Physiotherapy School
Lecturer: J. S. Kauki, BSc, MSc, on PhD, Email: [email protected].
Office ext. 70 Block C, 3
RD
Floor, Anatomy dept.

2. Outline
Objectives

Introduction, definition and general features of connective
tissues

Connective tissue cells

Connective tissue matrix fibers

Connective tissue Ground substances

Classification and description of different types of connective
tissues

Summary

3. CONNECTIVE TISSUES
Objectives:

Describethegeneralfeaturesofconnectivetissue.

Describethestructure,location,andfunctionofthe
varioustypesofconnectivetissue.

4. Connective tissue -Introduction
Connectivetissueisamongthemostabundantandwidely
distributedtissuesinthebody.
Beinginmanyforms,connectivetissuehasavarietyoffunctions:

Itbindstogether,supports,andstrengthensotherbodytissues.

Itprotectsandinsulatesinternalorgans.

Itcompartmentalizesstructuressuchasskeletalmuscles.

Blood,whichisafluidconnectivetissue,servesasthemajor
transportsystemwithinthebody.

5. General Features of Connective Tissue
Connective tissue consists of two basic elements:

Extracellular matrix and Cells.
Extracellular matrix

Is the material located between its widely spaced cells.

Consists of protein fibers (extracellular fibers) and ground substance
(extracellular matrix).

Extracellular fibers

Are secreted by the connective tissue cells

Determine the many functional properties of the tissue

Also controls the surrounding watery environment via specific proteoglycan
molecules

Ground substance / Extracellular matrixis the material between the cells
and the fibers, and
determines much of the tissue’s qualities. Eg.Cartilage is firm
but pliable while the bone is hard and inflexible.

Connective tissues usually are highly vascular, except cartilage which is
avascular and tendons which has scanty blood supply.

Except for cartilage, connective tissues are supplied with nerves.

6. Connective Tissue Cells
Embryonicmesenchymalcellsgiverisetothecellsofconnectivetissues.

Theimmatureconnectivetissuecells(~blast)are

Fibroblastsinlooseanddenseconnectivetissue,

Chondroblastsincartilage,and

Osteoblastsinbone.

Blastcellsretainthecapacityforcelldivisionandsecretetheextracellular
matrixwhichdeterminesthecharacteristicofthetissue.

Incartilageandbone,oncetheextracellularmatrixisproduced,the
immaturecellsdifferentiateintomaturecellswithnamesendingin-cyte,
namelychondrocytesandosteocytes.

Maturecells(~cyte)havereducedcapacitiesforcelldivisionandsecretion
ofextracellularmatrixandaremostlyinvolvedinmonitoringand
maintainingtheextracellularmatrix.

7. 
Fibroblasts

Macrophages

Plasma Cells

Mast Cells

Adipocytes
True Connective Tissue Cells

8. 
Macrophages:

Developfrommonocytes,atypeofwhitebloodcell.

Macrophageshaveanirregularshapewithshortbranchingprojections
andarecapableofengulfingbacteriaandcellulardebrisbyphagocytosis.

Fixedmacrophagesresideinaparticulartissue;examplesinclude
alveolarmacrophagesinthelungsorsplenicmacrophagesinthespleen.

Wanderingmacrophageshavetheabilitytomovethroughoutthetissue
andgatheratsitesofinfectionorinflammationtocarryoutphagocytosis.
Fibroblasts:
Arelarge,flatcellswithbranchingprocesses.

Arepresentinallthegeneralconnective
tissues,andusuallyarethemostnumerous.

Fibroblastsmigratethroughtheconnective
tissue,secretingthefibersandcertain
componentsofthegroundsubstanceofthe
extracellularmatrix.

9. Plasma cells

Are small cells that develop from B lymphocyte.

Plasma cells secrete antibodies, proteins that attack or neutralize foreign
substances in the body.

Thus, plasma cells are an important part of the body’s immune response.

Most plasma cells reside in connective tissues, especially in the
gastrointestinal and respiratory tracts although they are found in many
places in the body .

They are also abundant in the salivary glands, lymph nodes, spleen, and
red bone marrow.

Mast cells

Are abundant alongside the blood vessels that supply connective tissue.

They produce histamine, a chemical that dilates small blood vessels as
part of the inflammatory response, the body’s reaction to injury or
infection. In addition, researchers have recently discovered that mast
cells can bind to, ingest, and kill bacteria.

10. Adipocytes / Fat cells:

Areconnectivetissuecellsthat
storetriglycerides(fats).

Theyarefounddeeptotheskin
andaroundorganssuchasthe
heartandkidneys.

Whitebloodcells:

Arenotfoundinsignificantnumbers
innormalconnectivetissue.However,
inresponsetocertainconditionsthey
migratefrombloodintoconnective
tissues.Forexample,neutrophils
gatheratsitesofinfection,and
eosinophilsmigratetositesofparasitic
invasionsandallergicresponses.

11. Collagen Fibers:
•
Large fibers made of the protein collagen
and are typically the most abundant
fibers.
•
Promote tissue flexibility.
Elastic Fibers:
•
Intermediate fibers made of the protein
elastin.
•
Branching fibers that allow for stretch
and recoil
Reticular Fibers:
•
Small delicate, branched fibers that have
same chemical composition as collagen.
•
Forms structural framework for organs
such as spleen and
lymph nodes.

12. Clinical correlation
Marfansyndrome

Isaninheriteddisordercausedbyadefectivefibrillingene.

Theresultisabnormaldevelopmentofelasticfibers.

Tissuesrichinelasticfibersaremalformedorweakened.

Structuresaffectedmostseriouslyarethecoveringlayerofbones
(periosteum),theligamentthatsuspendsthelensoftheeye,andthewalls
ofthelargearteries.

PeoplewithMarfansyndrometendtobetallandhavedisproportionately
longarms,legs,fingers,andtoes.

Acommonsymptomisblurredvisioncausedbydisplacementofthelens
oftheeye.

Themostlife-threateningcomplicationofMarfansyndromeisweakening
oftheaorta(themainarterythatemergesfromtheheart),whichcanburst
suddenly.

13. Ground Substance
Isthecomponentofaconnectivetissuebetweenthecellsandfibers.
Thegroundsubstancemaybefluid,semifluid,gelatinous,orcalcified.

Itsupportscells,bindsthemtogether,storeswater,andprovidesamediumfor
exchangeofsubstancesbetweenthebloodandcells.

Itplaysanactiveroleinhowtissuesdevelop,migrate,proliferate,andchange
shape,andinhowtheycarryouttheirmetabolicfunctions.

Containswaterandanassortmentoflargeorganicmolecules,manyofwhich
arecomplexcombinationsofpolysaccharidesandproteins.

Thepolysaccharidesincludehyaluronicacid,chondroitinsulfate,dermatan
sulfate,andkeratansulfate.Collectively,theyarereferredtoas
glycosaminoglycans(GAGs).

Exceptforhyaluronicacid,theGAGsareassociatedwithproteinscalled
proteoglycans

TheproteoglycansformacoreproteinandtheGAGsprojectfromtheprotein
likethebristlesofabrush.

OneofthemostimportantpropertiesofGAGsisthat theytrapwater,
makingthegroundsubstancemorejellylike.

14. Hyaluronic Acid:
Complex combination of
polysaccharides and proteins
found in “true” or proper
connective tissue.
Chondroitin sulfate:
Jellylike ground substance of
cartilage, bone, skin and blood
vessels.
Other ground Substances:
Dermatin sulfate, keratin sulfate,
and adhesion proteins

15. Hyaluronic acid

Isaviscous,slipperysubstancethatbindscellstogether,lubricatesjoints,and
helpsmaintaintheshapeoftheeyeballs.

Whitebloodcells,spermcells,andsomebacteriaproducehyaluronidase,an
enzymethatbreaksaparthyaluronicacid,thuscausingthegroundsubstanceof
connectivetissuetobecomemoreliquid.

Theabilitytoproducehyaluronidasehelpswhitebloodcellsmovemoreeasily
throughconnectivetissuestoreachsitesofinfectionandaidspenetrationofan
oocytebyaspermcellduringfertilization.

Italsoaccountsfortherapidspreadofbacteriathroughconnectivetissues.

Chondroitinsulfateprovidessupportandadhesivenessincartilage,bone,skin,and
bloodvessels.

Theskin,tendons,bloodvessels,andheartvalvescontaindermatansulfate.

Bone,cartilage,andthecorneaoftheeyecontainkeratansulfate.

Adhesionproteinsareresponsibleforlinkingcomponentsofthegroundsubstance
tooneanotherandtothesurfacesofcells.

Themainadhesionproteinofconnectivetissueisfibronectin,whichbindsto
bothcollagenfibersandgroundsubstance,linkingthemtogether.

Fibronectinalsoattachescellstothegroundsubstance.

16. Clinical correlation

Inrecentyears,chondroitinsulfateandglucosamine(aproteoglycan)have
beenusedasnutritionalsupplementseitheraloneorincombinationtopromote
andmaintainthestructureandfunctionofjointcartilage,toprovidepainrelief
fromosteoarthritis,andtoreducejointinflammation.

Althoughthesesupplementshavebenefitedsomeindividualswithmoderateto
severeosteoarthritis,thebenefitisminimalinlessercases.Moreresearchis
neededtodeterminehowtheyactandwhytheyhelpsomepeopleandnot
others.

17. I.
Embryonic connective tissue

A. Mesenchyme

B. Mucous connective tissue
II.
Mature connective tissue
A. Loose connective tissue

1. Areolar connective tissue

2. Adipose tissue

3. Reticular connective tissue
B. Dense connective tissue

1. Dense regular connective tissue

2. Dense irregular connective tissue

3. Elastic connective tissue
C. Cartilage

1. Hyaline cartilage

2. Fibrocartilage

3. Elastic cartilage
D. Bone tissue

1. Compact bone

2. Cancellous (Spongy)
bone
E. Liquid connective tissue

1. Blood tissue

2. Lymph
Classification of Connective Tissues

18. Embryonic Connective Tissue
MESENCHYME

Consistsofirregularlyshaped
mesenchymalcellsembeddedina
semifluidgroundsubstancethat
containsdelicatereticularfibers.

Location:Foundalmostexclusivelyin
theembryo,underskinandalong
developingbonesofembryo;some
mesenchymalcellsarefoundinadult
connectivetissue,especiallyalong
bloodvessels.

Function:Formsalmostallothertypes
ofconnectivetissue

19. Connective Tissue cont…
Embryonic Connective Tissue
A. mesenchyme
B. mucous

20. Embryonic connective tissue
MUCOUS CONNECTIVE TISSUE

Description:Consistsofwidely
scatteredfibroblastsembeddedina
viscous,jellylikegroundsubstance
thatcontainsfinecollagenfibers.

Location:Umbilicalcordoffetus.

Function:Support.

21. 1.Loose Connective Tissue:
A) Areolar tissue
Widely distributed
under epithelia
B) Adipose tissue
Hypodermis, within
abdomen, breasts
C) Reticular connective
tissue
Lymphoid organs such
as lymph nodes
1.AreolarCT
•
Content:Consistsofall3typesoffibers
(Collagen,ElasticandReticular),
severaltypesofcells,andsemi-fluid
groundsubstance
•
Distribution:Foundinsubcutaneous
layerandmucousmembranes,and
aroundbloodvessels,nervesand
organs.
•
Function:Strength,supportand
elasticity

22. Loose Connective Tissue cont…….
2. Adipose tissue / Fat tissue

Content:Consistsof
adipocytes;"signetring"
appearingfatcellsthatstore
energyintheformof
triglycerides(lipids).

Distribution:Foundin
subcutaneouslayer,around
organsandintheyellow
marrowoflongbones

Function:Supports,Protects,
Insulates,andservesasan
energyreserve.

23. Loose Connective Tissue cont…:
3. Reticular CT

Content:Consistsoffine
interlacingreticularfibers
andreticularcells

Distribution:Foundin
liver,spleenandlymph
nodes

Function:Formsthe
framework(stroma)of
organsandbindstogether
smoothmuscletissue
cells

24. 2. Dense Connective Tissue:
•
Dense connective tissue contains
more numerous and thicker fibers
and far fewer cells than loose CT
A.
Dense regular connective tissue
•
Consists of bundles of collagen fibers
and fibroblasts
•
Forms tendons, ligaments and
aponeuroses
•
Function: Provide strong
attachment between various
structures

25. :
B.
Dense irregular connective
tissue

Consists of randomly-arranged
collagen fibers and a few
fibroblasts

Found in fasciae, dermis of skin,
joint capsules, and heart valves
submucosa of digestive tract

Function: Provide strength

26. ELASTIC CONNECTIVE TISSUE
Consistspredominantlyofelasticfiberswith
fibroblastsinspacesbetweenthefibers.

Location:Lungtissue,wallsofelastic
arteries,trachea,bronchialtubes,truevocal
cords,suspensoryligamentsofpenis,and
someligamentsbetweenvertebrae.

Function:Allowsstretchingofvarious
organs.Elasticconnectivetissueisquite
strongandcanrecoiltoitsoriginalshape
afterbeingstretched.

Elasticityisimportanttothenormal
functioningoflungtissue,whichrecoilsas
youexhale,andelasticarteries,whichrecoil
betweenheartbeatstohelpmaintainblood
flow.

27. Supportive Connective Tissue:
CARTILAGE:

Jelly-likematrix(chondroitin
sulfate)containingcollagenand
elasticfibersandchondrocytes
surroundedbyamembranecalled
theperichondrium.

UnlikeotherCT,cartilagehasNO
bloodvesselsornervesexceptin
theperichondrium.

Thestrengthofcartilageisdueto
collagenfibersandtheresilienceis
duetothepresenceofchondroitin
sulfate.

Chondrocytesoccurwithinspacesin
thematrixcalled lacunae.

28. 3 Types of Cartilage
1.
Hyaline cartilage
2.
Fibrocartilage
3.
Elastic cartilage

29. Supportive Connective Tissue cont….
1.Hyaline Cartilage

Isthemostabundanttype

Containfinecollagen
fibersembeddedinagel-
typematrix.Occasional
chondrocytesinside
lacunae.

Foundinembryonic
skeleton,attheendsof
longbones,inthenoseand
inrespiratorystructures.

Function:Providessupport
andallowsmovementat
joints

30. Supportive connective tissue cont…
2.Fibrocartilage

Containsbundlesofcollagen
inthematrixthatareusually
morevisibleunder
microscopy.

Foundinthepubicsymphysis,
intervertebraldiscs,and
meniscioftheknee.

Function:supportandfusion,
andabsorbsshocks.

31. 3.
Elastic Cartilage

Threadlikenetworkofelastic
fiberswithinthematrix.

Foundinexternalear,auditory
tubes,epiglottis.

Function:Givessupport,
maintainsshape,allows
flexibility
Supportive connective tissue cont…

32. Application: Tissue Engineering Technology
Thetechnologyoftissueengineering,whichcombinessyntheticmaterial
withcells,hasallowedscientiststogrownewtissuesinthelaboratoryto
replacedamagedtissuesinthebody.

Tissueengineershavealreadydevelopedlaboratory-grownversionsofskin
andcartilageusingscaffoldingbedsofbiodegradablesyntheticmaterialsor
collagenassubstratesthatpermitbodycellstobecultured.

Asthecellsdivideandassemble,thescaffoldingdegradesandthenew,
permanenttissueisthenimplantedinthepatient.

Otherstructurescurrentlyunderdevelopmentincludebones,tendons,heart
valves,bonemarrow,andintestines.

Workisalsounderwaytodevelop insulin-producingcellsfordiabetics,
dopamine-producingcellsforParkinsondiseasepatients,andevenentire
liversandkidneys
.

33. BONE TISSUE
Bonesareorganscomposedofseveraldifferent
connectivetissues,includingboneorosseous
tissue,theperiosteum,redandyellowbone
marrow,andtheendosteum(amembranethat
linesaspacewithinbonethatstoresyellowbone
marrow).

Bonetissueiseithercompactorspongy,
dependingonhowitsextracellularmatrixand
cellsareorganized.

ThebasicunitofcompactboneisanOSTEON
orhaversiansystem.Eachosteonhasfourparts:

1.Thelamellae(singularislamella)are
concentricringsofextracellularmatrixthat
consistofmineralsalts(mostlycalciumand
phosphates),whichgiveboneitshardnessand
compressivestrength,andcollagenfibers,which
giveboneitstensilestrength.
Thelamellaeare
responsibleforthecompactnatureofthis
typeofbonetissue.

34. 2.Lacunae(singularislacuna)aresmallspaces
betweenlamellaethatcontainmaturebonecells
calledosteocytes.

3.Canaliculi:Projectingfromthelacunae(little
canals),networksofminutecanalscontainingthe
processesofosteocytes.Canaliculiprovideroutes
fornutrientstoreachosteocytesandforwastesto
leavethem.

4.Acentral(haversian)canalwhichcontains
bloodvesselsandnerves.

Spongy bone lacks osteons. Rather, it consists of
slender columns of bone called trabeculae),
which contain lamellae, osteocytes, lacunae, and
canaliculi.

Spaces between trabeculae are filled with red bone
marrow.

Bone function: Support, protection, storage; houses blood-
forming tissue; serves as levers that act with muscle tissue to
enable movement.

35. Liquid Connective Tissue
Bloodtissue(orsimplyblood)isaconnectivetissue
withaliquidextracellularmatrixandformed
elements.

Theextracellularmatrixiscalledbloodplasma.

Thebloodplasmaisapaleyellowfluidthat
consistsmostlyofwaterwithawidevarietyof
dissolvedsubstances;nutrients,wastes,enzymes,
plasmaproteins,hormones,respiratorygases,and
ions.

Suspendedinthebloodplasmaare formed
elements;redbloodcells(erythrocytes),whiteblood
cells(leukocytes),andplatelets(thrombocytes).

Redbloodcellstransportoxygentobodycellsand
removesomecarbondioxidefromthem.

Whitebloodcellsareinvolvedinphagocytosis,
immunity,andallergicreactions.

Plateletsparticipateinbloodclotting.

36. LiquidConnectiveTissuecont……
LYMPH

Lymphistheextracellularfluidthatflowsinlymphaticvessels.

Thisconnectivetissueconsistsofseveraltypesofcellsinaclear
liquidextracellularmatrixthatissimilartobloodplasmabutwith
muchlessprotein.

Thecompositionoflymphvariesfromonepartofthebodyto
another.Forexample,lymphleavinglymphnodesincludesmany
lymphocytes,atypeofwhitebloodcell,incontrasttolymphfrom
thesmallintestine,whichhasahighcontentofnewlyabsorbed
dietarylipids.

37. In Summary
We have;

Describedthegeneralfeaturesofconnectivetissues.

Described Connective tissue cells

Described connective tissue matrix fibers

Described Connective tissue Ground substances

Classified and described different types of connective
tissues

38. Questions?

39. THANK YOU FOR YOUR ATTENTION