▁col lagen ▁III ▁pre domin ates ▁in ▁the ▁gran ulation ▁t issue ▁which ▁later ▁on ▁in ▁rem od eling ▁phase ▁gets ▁replaced ▁by ▁col lagen ▁I ▁giving ▁additional ▁tens ile ▁strength ▁to ▁the ▁he aling ▁t issue . ▁It ▁is ▁evident ▁from ▁the ▁known ▁col lagen ▁assembly ▁that ▁the ▁tens ile ▁strength ▁is ▁basically ▁due ▁to ▁f ibr ill ar ▁arrangement ▁of ▁col lagen ▁mole cules , ▁which ▁self - ass emble ▁into ▁micro f ibr ils ▁in ▁a ▁longitud inal ▁as ▁well ▁as ▁later al ▁manner ▁producing ▁extra ▁strength ▁and ▁stability ▁to ▁the ▁col lagen ▁assembly . ▁Met abol ically ▁alter ed ▁col lagen ▁is ▁known ▁to ▁be ▁highly ▁inf lex ible ▁and ▁pr one ▁to ▁break ▁down , ▁particularly ▁over ▁pressure ▁areas . ▁F ib ron ect in ▁is ▁the ▁major ▁g ly cop rote in ▁secret ed ▁by ▁fib ro bl asts ▁during ▁initial ▁synth esis ▁of ▁ext rac ell ular ▁matrix ▁prote ins . ▁It ▁serves ▁important ▁functions , ▁being ▁a ▁chem o - att ract ant ▁for ▁macro ph ages , ▁fib ro bl asts ▁and ▁end oth el ial ▁cells . ▁ ▁Bas ement ▁memb rane ▁that ▁separ ates ▁e pid erm is ▁from ▁the ▁der mal ▁layer ▁and ▁end oth el ial ▁bas ement ▁memb rane ▁mainly ▁contain ▁col lagen ▁IV ▁that ▁forms ▁a ▁sheet ▁and ▁bind s ▁to ▁other ▁extra ▁cell ular ▁matrix ▁mole cules ▁like ▁l amin in ▁and ▁prote og ly c ans . ▁In ▁addition ▁to ▁col lagen ▁IV , ▁e pid