connective tissue-gowri-1

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SEMINAR ON

CONNECTIVE TISSUE

DR.GOWRI ARUN P.G. STUDENT

V.S.D.C.H


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ContentsIntroductionOriginDifference between epithelium & connective tissueTypes of connective tissueStaining of connective tissueComposition Of Connective Tissue

Cellular ComponentsExtracellular MatrixGround SubstanceFibres


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CONTENTS

Types of connective tissueconnective tissue proper

connective tissue with special propertiessupporting connective tissueCollagen

Structure

Types And ClassificationBiosynthesis Of CollagenUses Of Collagen

non collagenous proteins

Ground substance


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CONTENTS

Gingival Connective TissuePeriodontal Connective TissueCementumAlveolar BoneHealingConclusion

Reference


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TISSUE

Defined as collection of specialised cells and cellproducts organised to perform a limited number offunctions.

Levels of OrganizationsCELLTISSUESORGANSORGAN SYSTEMSORGANISMS


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F OUR TYPES O F TISSUES

EPITHELIALCONNECTIVE TISSUE

MUSCULAR TISSUENERVOUS TISSUE


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CONNECTIVE TISSUE

Connective tissue may be defined as that group of tissuespredominantly composed of intercellular matrix ,secretedmainly by its cells which are therefore widely spaced.

It is mesodermal in origin and provides structural andmetabolic support for other tissue and organs through out thebody .


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EPITHELIUM CONNECTIVE TISSUE

CELLS ARE COMPACT LY ARRANGED LOOSE LY ARRANGED

NO INTERCELLULAR SPACE LARGE

HIGHLY REDUCED MATRIX LARGE INTERCELLULAR MATRIX

CELLS REST ON BASEMENTMEMBRANE

NO BASEMENT MEMBRANE

AVASCU LAR CONTAINS B LOOD VESSE LS

DERIVED FROM 3 GERM LAYERS FROM MESODERM


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COMPOSITION

CELLULAR COMPONENTS

Cells that are intrinsic components of connective tissueFibroblastsUndifferentiated mesenchymal cellsPigment cellsFat cells

Cells that belong to immune systemmacrophageslymphocytesMast cellPlasma cellMonocytes

eosinophils


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EXTRACELLULAR COMPONENTS

Fibres in conne ct ive t issueCollagenElasticReticular

Ext ra cellular ma t rixCollagenous proteinsNon collagenous proteins

proteoglycan


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F UNCTIONS O F CONNECTIVE TISSUE

St ru ct ural Fun ct ions:Loose C.T : holds together structures like skin, muscles , bloodvessels and various layers of viscera.

Areolar & Reticular tissues : Framework that supports cellular elements of various organs like spleen, lymphnodes, glands andprovides capsules for them.

Looseness of areolar tissue facilitates movement betweenstructures


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Superfiscial fascia : enables movement of skin over deepfascia.

Deep fascia : provides tight covering for deeper structures

Ligaments : hold bone ends together at joints.

Tendons : transmit pull of muscles t o their origin.


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Defensive r ole [Macrophages,plasma cells]

T r oph ic and mor phog enic r ole : In organising andinfluencing the growth and differentiation of surroundingtissues.

I nsula t ion and t rans po r t a t ion [blood] : Adipocytes areused for cushioning, thermal insulation, lubricationand energy storage .


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STAINING O F CONNECTIVE TISSUE

Von giesons stain

Massons trichrome stain

Mallorys aniline blue stain

Azocarmine stain

Krajians aniline blue stain


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CLASSI F ICATION

C.T PROPERSPECIAL

PROPERTIESSUPPORTING

LOOSE

DENSE-

REGULAR

IRREGULAR

ADIPOSE

ELASTIC

MUCOUS

HAEMOPOIETICRETICULAR

BONE

CARTILAGE


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TYPES OF CONNECTIVE TISSUE


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LOOSE CONNECTIVE TISSUE

Bundles of loosely arranged fibres appear to enclose largespacesGel like matrix with all three fibre types, i.e. collagen, reticular,elastic.


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LOOSE C.T

CELLS : varied cell populationFibroblasts

MacrophageAdipocytesMesenchymal cellsMelanocytesMast cellsLymphocytesMicrophages

ECM : hyaluronan and proteoglycans


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LOOSE CONNECTIVE TISSUE

Locat ion : widely distributed under epithelia of body.e.g. Forms lamina propria of mucous membrane;

Packages organs;

Surrounds capillaries.


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LOOSE C.T

Fun ct ions :Wraps and cushions organsMacrophages phagocytoze bacteriaPlays important role in inflammationHolds and conveys tissue fluid


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D ENSE CONNECTIVE TISSUE

DENSE REGULAR CONNECTIVE TISSUE :

Densely aligned parallel fibersMajor cell type is fibroblast.


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Location : Tendons, Ligaments, Aponeuroses

Function : Attaches muscle to bonesBinds bone to boneResists tension


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DENSE IRREGULAR CONNECTIVE TISSUE :

Locat ion :Dermis of the skin,Fibrous capsules around organs and joints

Submucosa of digestive tractFun ct ion : Withstand tension exerted in many directions

Provides structural strength


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CONNECTIVE TISSUE WITH SPECIALPROPERTIES

ADIPOSE TISSUE :- closely packed adipocytes or fat cellsnuclei pushed to the side by fat droplets

Compromise 15-25% of body tissue


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ADIPOSE TISSUE

Loca t ion :Mostly in superficial fasciaPaniculus adiposus-subcutaneous

Around kidneysBehind the eyeballsIn bones,abdomen,On the surface of heart & around joints


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ADIPOSE TISSUE

Types :Unilocular /white /yellow fat :

single droplet of fat in cytoplasm.

facilitate storage and release of triglycerides

Multilocular or brown fat :large number of small lipid vescicles

Abundant - newborn &- hibernating animals


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ADIPOSE TISSUE

Fun ct ions :Cushions joints and some organs like kidneysInsulates beneath the skinStores energy in fat molecules


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RETICULAR TISSUE

Has network of reticular fibers [type-III collagen fibers] in loose groundsubstanceDiffer from type I collagen fiber by

- finer,

-uneven thickness,- form a network by branching & anastomosing- argentophillic fibres.


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RETICULAR TISSUE

Locat ion :Marrow, Spleen, Lymph nodes,Liver, kidneys, smooth muscle and nerve fibers

Fun ct ions :Supporting network (spleen, lymphnodes, bone marrow)Basement membane


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ELASTIC TISSUE

Elastic tissue is yellow in colour

Elastic fibres are seen in parallel strands or in branching networksCollagen fibres & fibroblasts found in between elastic fibersCan be stretchedHighly refractile


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ELASTIC TISSUE

St ainin g : orcein,aldehyde fuschinverheoffs method

Locat ion:Eg: ligamentum nuchae

Ligamentum flavaVocal ligamentsWalls of large arteries

Smaller arteries - internal elastic lamina


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ELASTIC TISSUE

Fun ct ions :

Imparts the strength, extensibility and elastic quality to

structures

Holds the parts together

Prevents excessive dilatation of blood vessels


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HA EMOPOIETIC

H ae mopo iet ic t issue : Myel oid t issue

Lympho id t issue

Myel oid t issue Myeloid tissue is a biological tissue with the ability to perform

mainly haematopoesis as in red bone marrow of bones.It includes

-Phagocytic and blood forming cells

- plasma and platelets

- liver and spleen.


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Lympho id t issue: Structural organizations concerned with immune response.

Location : thymus and lymph nodes, spleen.Has a cylinder of loosely organized cells surrounding small

arteries.

Most diffuse lymphoid tissue is seen in the loose CT spaces

beneath wet epithelial membranes - GIT & respiratory systems


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SUPPORTING CONNECTIVE TISSUE

CARTILAGE

- Specialized form of connective tissue :

- Form skeletal basis for some parts of the body.- Avascular & devoid of nerves

Compo sit ion

Cells : chondrocytesMatrix : collagenous fibers& ground substance.Groundsubstance : Proteins&Carbohydrates

Chondronectin (major adhesion protein)Chondrotin sulphateHyaluronic acid


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CARTILAGE

Fun ct ions:Tissues to bear mechanical stressesGives support to the soft tissuesShock absorbing and sliding area for joints andfacilitates bone movement.For the development and growth of long bonesbefore and after birth


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CARTILAGE

Gr owth : Occurs by 2 mechanism,

Interstitial growth : initial phase of cartilage formation.

- Chondroblasts within the cartilage divide & secretematrix

-growth occurs from within the cartilage.

Appositional growth :Chondroblasts - deep to the perichondriumdeposit new matrix on surface of exisiting cartilage str.

Both the growth processes continue until the bony skeleton stopsgrowing at the end of adolescence


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TYPES O F CARTILAGE

Hyaline cartilage

Elastic cartilage

Fibrocartilage


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HYALINE CARTILAGE

Most abundant type

Bluish-white and translucent

In embryo, serves as the temporary skeleton


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HYALINE CARTILAGE

Location :Covers the ends of long bones - articular cartilage,

Tip of the nose

Connects the ribs to the sternumForms laryngeal cartilages- thyroid, cricoid and arytenoidSupporting cartilages of the trachea and bronchial tubesPersists during childhood as the epiphyseal plates


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M a t rix40 % of dry wt. collagen(type II )

embedded in a firm, hydrated gel of proteoglycans &glycoproteins.

P r ot eog l ycans : chondroitin 4-sulfate, chondroitin 6-sulfate, &

keratan sulfate, covalently linked to core proteins.

St ru ct ural g l ycop r ot ein : chondronectin


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ELASTIC CARTILAGE

ELASTIC [y ell ow fibr ocar t ila g e] Contains abundant fine elastic fibersCollagen type II fibers.

Fresh elastic cartilage yellowish in color - elastin in fibersCovered by perichondrium


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ELASTIC CARTILAGE

Locat ion : Auricle of the ear Lateral part of external auditory canal

Auditory (eustachian)tubes-wall of medial partEpiglottisCuneiform & corniculate cartilage in the larynx

Fun ct ion : Provides supportTolerates distortion without damage and returns to originalsupport


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F IBROUS CARTILAGE

Dense white fibrous tissue having cartilage cells surrounded bycapsuleHas no perichondriumHas great tensile strength with considerable elasticity.Rows of chondrocytes alternating with rows of thick collagenfibers [TYPE-I]


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F IBROUS CARTILAGE

Fun ct ion : Resists compressionPrevents bone-to-bone contactLimits relative movement


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F IBROUS CARTILAGE

Locat ion : Intervertebral discs (resilient cushions between the bonyvertebrae)Spongy cartilages of the knee and in pelvic girdlePubic symphysesHip jointTMJ, sternolavicular & menisci of knee joint


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BONE

BONE :

Specialized connective tissue composed of intercellular

calcified matrix. BONE

33 % ORG 67 % INORG

28 % CO LLAGEN5 % NON

CO LLAGENOUSPROTEIN

HYDROXYAPATITECa1 0(PO 4)6(OH)2


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B ONE

C ells :-Osteoblasts synthesize - organic components of matrix

-Osteocytes, found in lacunae within the matrix

-Osteoclasts, multinucleated giant cells - resorption andremodeling of bone tissue - lie within depressions in the matrix

known as Howships lacunae.


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INORGANIC MATTER :

-abundant calcium & phosphorus

-bicarbonate , citrate, magnesium, potassium, sodium,flouride, chloride

OSTEOID : uncalcified matrix-seperates the osteoblasts from

calcification front of mineralised bone


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BONE

ORGANIC MATTER : composed of collagen fibres, groundsubstance, interstitial fluid & free electrolytes

Mature : TypeI collagen

Gr ound subs t an ce: GAGs, proteoglycans, water ,GPs


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TYPES O F BONE :

By shape : Flat, Irregular, Short, and Long

By origin : Endochondral, Dermal, Alveolar, Sesamoid /Wormian


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BONE HISTOLOGY :

Dense outer sheet of compact bone

Central medullary cavity

The cavity is filled with red or yellow bone marrow

Outer aspect compact bone is connective tissue membrane, theperiosteum which has 2 layers-outer fibrous layer &inner cellular

layer

The internal surfaces are covered by essentially cellular

membrane, the endosteum


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BONE

Comp act bone : dense areas without cavities-Deposited in thin layers called lamellae- form concentric patterns

around capillaries -located within tiny longitudinal tubes called

central / Haversian canals .

-The canal, branch and anastomose with each other and with the

external surface of bone.

-Osteocytes and layers of intercellular material are concentrically

clustered around central canal to form a cylinder-shaped unit

called Osteon, or Haversian system.


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C an cell ous bone : Beams or trabeculae of mineralised bone

The long axis of each trabeculae is generally oriented at 9 0 to the

forces of muscle tension & weight bearing

Has a light, honeycomb structure

Trabaeculae are arranged in the directions of tension and

compression and made of a number of lamellae.

Occurs in the heads of the long bones, vertebrae


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B ONE

F ORMATION O F BONE :It occurs by two methods :

IntramembranousEndochondral

INTRAMEMBRANOUS OSSI F ICATION Eg : most of the fla t bones

Direct mineralization of matrixWithin mesenchymal condensation

Contributes to growth of short bones and thickening of long bones

ENDOCHONDRAL :Deposition of bone matrix on a preexisting cartilage matrixFormation of short and long bones


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CELLULAR COMPONENTS O F CONNECTIVE TISSUE

FIBROBLASTMACROPHAGESMAST CELLPERICYTESPIGMENT CE LLADIPOCYTEBONE CE LLCARTILAGE CE LL


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F IBROBLASTS


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F IBROBLASTS

y In young and active cells, the cytoplasm is abundant and

basophilic

y Nucleus is ovoid, large and pale-staining, mitochondria are

abundant and several sets of Golgi complexes are present.

y Old and inactive fibroblasts f ibrocytes

-cytoplasm - sparse,

-ER - scanty,

-nucleus flattened & heterochromatic

(close-faced).


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F UNCTIONS O F F IBROBLASTS

Synthesize collagen, elastin, glycosaminoglycans,

proteglycans and glycoproteins of extracellular matrix

production of growth factors

In glands and lymphoid tissue, fibroblasts & reticulin fibres

fibrocellular networks.

wound repair- fibrous matrix.

Contraction of wounds (myo f ibroblasts)


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MACROPHAGES (HISTIOCYTES ,CLASMATOCYTES )

Bone marrow blood stream (monocytes)

CT(Macrophages)

change their appearance-phagocytic activityFixed

Motile when stimulated.

When grouped around a large foreign body,macrophages fuse - syncytial giant cells and epithelioid

cells.


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MACROPHAGES

Kidney bean shaped nucleus large

prominent nucleoli

15-2 0 m in diameter More lysosomes

Ingested materials in the cytoplasm

Fuzzy cell border (outline)

lamina propria of the oral mucosa 2 types - melanophage

and the siderophage.


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MAST CELLS

defensive cellsLocation : in loose CT

liver blood vesselsnerves

Round or oval12 um in diameter many filopodia - cell surface

vesicles - metachromatic staining reactions acid GAGcontentSecretory granules : 0 .3-2. 0 m in diameter


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MAST CELLS

M aj or Granule Compo nen t s :

Histamine,

Proteoglycan , Heparin

T ryptase, Superoxide D ismutase, A ryl Sulphatase,

Other Enzymes: Eosinophil C hemotactic Factors & N eutrophil

C hemotactic Factors.

Release Leukotrienes (C 4 , D 4 , E4) Or Slow-reacting Substance Of

Anaphylaxis (Srs-a).


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MAST CELLS

M edical applica t ions :

Storage of chemical mediators - immediate hypersensitivity

reaction e.g. anaphylactic shock

Histamine- smooth muscle contraction, dilates and increases

vascular permeability

Heparin released by mast cells is an anticoagulant


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LYMPHOCYTES

Present in small numbersnumerous in pathological states from lymphoid /circulation.

Rounded, highly heterochromatic or often deeply indented

nucleiWhen appropriately stimulated they enlarge, developingnumerous ribosomes.Large lymphocytes- 1 0-12 micronsSmall lymphocytes- 7-1 0 microns

2 Types- T lymphocytes & B lymphocytesT lymphocytes CE LLMEDIATED IMMUNITY

B lymphocytes HUMORA L IMMUNE RESPONSE


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PLASMA CELLS

Rounded or ovoid 15um

Egg-shaped cell with clear outline

Basophilic cytoplasm

Eccentrically located nucleus

Cartwheel appearance, spherical

abundant endoplasmic reticulum.

Short life span, 1 0-20 days


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NEUTROPHILS &EOSINOPHILS

Immigrant cells from the circulation

small numbers, increases in number in infected tissues

Neutrophils are highly phagocytic, esp towards bacteria

Eosinophils are increased in allergic response and parasitic

infections


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MELANOCYTES

F ound in basal and suprabasal layer of epidermisConcerned with synthesis of melanin pigmentiris and choroid of the eye

chr omatopho res/ melan opho res:s t ars haped-modified fibr oblas t s eng ulf pigment released b y other cellsPevent light from reaching adjacent cells


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Next session:Extra cellular componentsCollagen

Non collagenous proteinsGround substancePeriodontal connective tissuesConclusionReferences


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ACKNOWLEDGEMENT

I thank all the staff members ,seniors & my

batchmates of department of periodontics, V .S.

dental college & hospital, Bangalore who helped mein this presentation


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RE F ERENCES

O ral Histology-cell Structure & F unction DAVISO ral Histology- INDERBER SINGHC ARRANZA S C LIN ICA LP ERIOD O N TOLOGY T EN C AT ES OR A L HISTOLOGY Human P hysiology Guyton & Hall


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THANK YOU


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Seminar on connective tissue

by Dr. Gowri Arun V.S.D.C.H


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Extracellular M atrix Ground SubstanceFibres

Collagen StructureTypes And Classification

Biosynthesis Of CollagenUses Of Collagen

Proteoglycan -glycosaminoglycans and core proteinsNON COLLAGENOUS PROTEINS

ELASTINy FIBRONECTINy

LAMININSy NIDOGENy TENASCINy THROMBOSPONDINy VITRONECTINy OSTEOPONTINy SPARC(OSTEONECTIN)y OSTEOCA LCINy BONE SIALOPROTEIN


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