Connective Tissue

DR. KIRTI SOLANKE

Connective Tissue• Found everywhere

• Most abundant

• Development

• Functions– Protection– Support– Bind other tissues– Energy storage/insulation– Hormone production

COMPONENTS

LIVING NON - LIVING

CELLS MATRIX

FIXED WANDERING

FIBROBLASTS

FAT CELLS

PERSISTANT MESENCHMAL CELLS

MACROPHAGES

MAST CELLS

PLASMA CELLS

PIGMENT CELLS

NEUTROPHILS

EOSINOPHILS

FIBRES GRD SUBS

COLLAGEN

ELASTIN

RETICULAR

MPS

SO4

NON-SO4

GLYCO PR

Fibers

• Collagen/ white fibers

• Elastic/yellow fibers

• Reticular fibers/Argyrophilic – fine collagen fibers

COLLAGEN FIBRES

• In bundles branch,1-12um in dia, White• H &E and Van Gieson:pink;masson’s

T:blue;• Tensile force,birefringence,swell with weak

alkali,boiling convert it into gelatin.• Synthesis:fibroblast,regulation,degradation(

MMP)• Made of tropocollagen mol;made of 3

polypeptide chains(procollagen)

SYNTHESIS

• AA taken up by cells& linked PROα CHAINS αchain 3chains join to form PROCOLLAGEN MOL such mol leave cell through secretory vacuoles to form TROPOCOLLAGEN MOL aggregate to form COLLAGEN FIBRILS.(vit C,oxy)

• Fibrillogenesis

TYPESTYPE LOCATION

I(250nm dia) SKIN,BONE,TENDON,FASCIA,CAPSULE

II(20 to 100nm) HYALINE CARTILAGE ,NOTOCHORD,INTERVERTEBRAL DISC

III RETICULAR FIBRES,FETAL SKIN,BLOOD VESSEL.

IV BASAL LAMINA,KIDNEY GLOMERULI

RETICULAR FIBRES(Argyrophilic)

• Collagen type III,Striation(68ηm),20ηm diameter,do not bundle,uneven in thickness.

• Form network by branching• Silver impregnation:black but type I:brown • H&E:not identified;• More carbohydrates:PAS• Early mechanicalstrenth,delicate,suporting

stroma in lymphatic T.(not thymus)• Synthesis:reticular cells

RETICULAR FIBRES

ELASTIC FIBRES

• Run singly,branches,0.1-0.2μm in dia• Not well stained H&E;Certain fixative make

them refractile then can be visualised• Composed of:central core of elastin &

surrounding network of fibrillin microfibril• Lacks hydroxylysine,random distribution of

glysine:HYDROPHOBIC & random coiling.• Vertebral ligaments,larynx,elastic A

WEIGERT’S STAIN

GROUND SUBSTANCE

• Glycoprotiens:keratan s

• Multiadhesive glycoproteins:laminin,fibronectin

• Proteoglycans:aggrecan,decorin

Pr + long chain polysaccharide –glycosoaminoglycans (MPS)

» Sulphated» Non sulphated

Ground Substance

• GSG linked with pr.

• Carry sulphate gr(so3-)Carboxyl gr(coo-).

• Thus proteoglycans r in long chain,

• Can retain water thus proteoglycans form

• semi-solid, gel:stiffness

• Molecular arrangement: sieve

• Barrier:kidney;gas exchange:lungs

GLYCOSAMINOGLYCANS

TISSUE CHONDROITIN SULPHATE

DERMATAN SULPHATE

HEPARAN SULPHATE

HEPARIN

KERATAN S.

HYALURNIC ACID

TYPICAL CT

+ +

CARTILAGE

+ + +

BONE +

SKIN + + + +

BASEMENT M

+

OTHERS B/V LUNGS MAST C CORNEAINTER V DISC

SYNOVIAL FLUID

HYALURONIC ACID

• Hyaluronan:free carbohydrate chain

• Polymers r very large

• Synthesized by enzymes &not posttranslatioally modified

• No sulfate,proteoglycan aggregates

• So cartilage resist compression without inhibiting flexibility

CELLS

• FIXED TYPE:Fibroblast,Persistant mesenchymal cells,Adipocytes.

• WANDERING CELLS:Lymphocyte,Monocyte,Mast cell,Macrophages,Neutrphil,Plasma cell,Eosinophils.

FIBROBLAST ADIPOCYTE

MACROPHAGE

MAST CELL

LYMPHOCYTE

PLASMA CELL

CLASSFICATION OF C. T.

• Types of cells

• Types of fibres

• Amount of ground subs

CLASSIFICATION

CONNECTIVE TISSUE

ADULT C. T. FETAL C. T.

ORDINARY SPECIALISED

BLOOD

CARTILAGE

BONE

LOOSE C. T. DENSE C.T.

WHITE YELLOWAREOLAR

ADIPOSE

RETICULAR

REGULAR IRREGULAR

TENDON

LIGAMENT

APONEUROSIS

S/C TISSUE

FETAL C.T:WARTON’JELLY

LOOSE AREOLAR T.

Loose Connective• Areolar Tissue

– Gel like matrix – Fibroblasts, mast cells– Collagen, elastic and reticular fibers– Functions to wrap and cushion organs– Found in the lamina propria, around organs,

capillaries

Dense Connective

• Dense Regular– Parallel collagen fibers

with a few fibroblasts and a few elastin fibers

– Attach muscles to bones

– Great tensile strength in one direction

– Tendons and ligaments

DENCE REGULAR C.T.

TENDON

Dense Connective

• Dense irregular– Collagen fibers with a few elastic fibers

haphazardly arranged– Strong in many directions– Dermis, joint capsules, submucosa of

digestive tract

DENCE IRREGULAR C.T.

ADIPOSE TISSUE

APPLIED

• SCURVY:Vit C DEFICIENCY

• OSEOGENESIS IMPERFECTA:Brittle bone disease,blue sclera hearing loss,TYPE I asso

• EHLERS-DANLOS :hypermobility of joints of digit,TYPE III asso

• MARFAN’S S:FBN1,fibrillin gene