▁infl amm ation , ▁may ▁lead ▁to ▁t issue ▁sw elling ▁( ed ema ). ▁Alter ed ▁bar rier ▁function ▁is ▁also ▁imp licated ▁in ▁cancer ▁extra vas ation . ▁ ▁End oth el ial ▁cells ▁are ▁involved ▁in ▁many ▁other ▁aspects ▁of ▁vessel ▁function , ▁including : ▁Blood ▁cl ot ting ▁( th rom b osis ▁& ▁f ibr in ol ysis ). ▁The ▁end oth el ium ▁normally ▁provides ▁a ▁surface ▁on ▁which ▁blood ▁does ▁not ▁cl ot , ▁because ▁it ▁contains ▁and ▁express es ▁subst ances ▁that ▁prevent ▁cl ot ting , ▁including ▁he par an ▁sul f ate ▁which ▁acts ▁as ▁a ▁c of actor ▁for ▁activ ating ▁ant ith rom bin , ▁a ▁prote ase ▁that ▁in activ ates ▁several ▁factors ▁in ▁the ▁co ag ulation ▁cas cade . ▁In fl amm ation . ▁End oth el ial ▁cells ▁act ively ▁signal ▁to ▁white ▁blood ▁cells ▁of ▁the ▁imm une ▁system ▁during ▁infl amm ation ▁ ▁Form ation ▁of ▁new ▁blood ▁vessels ▁( ang i ogen esis ). ▁ ▁Con str iction ▁and ▁en larg ement ▁of ▁the ▁blood ▁vessel , ▁called ▁v aso con str iction ▁and ▁vas od ilation , ▁and ▁hence ▁the ▁control ▁of ▁blood ▁pressure ▁ ▁Blood ▁vessel ▁formation ▁The ▁end oth el ium ▁is ▁involved ▁in ▁the ▁formation ▁of ▁new ▁blood ▁vessels , ▁called ▁ang i ogen esis . ▁ ▁An gi ogen esis ▁is ▁a ▁cru cial ▁process ▁for ▁development ▁of ▁org ans ▁in ▁the ▁emb ry o ▁and ▁fet us ,