▁of ▁le uk ocy tes , ▁plate let ▁cells , ▁and ▁end oth el ial ▁cells ▁that ▁bind s ▁memb rane - bound ▁g ly c ans . ▁ ▁In ▁response ▁to ▁an ▁injury , ▁end oth el ial ▁cells ▁will ▁express ▁select in , ▁which ▁bind s ▁to ▁g ly c ans ▁present ▁on ▁the ▁le uk ocy te ▁cell ▁surface . ▁ ▁Pl ate let ▁cells , ▁which ▁are ▁involved ▁in ▁t issue ▁repair , ▁use ▁their ▁select ins ▁to ▁associate ▁with ▁le uk ocy tes ▁on ▁the ▁way ▁to ▁the ▁end oth el ial ▁cells . ▁ ▁Le uk ocy tes ▁then ▁use ▁their ▁own ▁select ins ▁to ▁recognize ▁potential ▁path og ens ▁at ▁the ▁site ▁of ▁the ▁injury . ▁ ▁In ▁this ▁manner , ▁the ▁appropriate ▁cells ▁are ▁brought ▁to ▁the ▁site ▁of ▁an ▁injury ▁to ▁deal ▁with ▁immediate ▁repair ▁or ▁inv ading ▁micro organ isms . ▁ ▁Bi ological ▁functions ▁for ▁extr insic ▁recognition ▁ ▁Path ogen ▁recognition ▁in ▁the ▁imm une ▁system ▁C ells ▁with ▁imm une ▁system ▁recognition ▁ab ilities ▁include ▁macro ph ages , ▁dent rit ic ▁cells , ▁T ▁cells , ▁and ▁B ▁cells . ▁Cell – cell ▁recognition ▁is ▁especially ▁important ▁in ▁the ▁inn ate ▁imm une ▁system , ▁which ▁ident ifies ▁path og ens ▁very ▁generally . ▁ ▁Central ▁to ▁this ▁process ▁is ▁the ▁binding ▁of ▁pattern ▁recognition ▁re cept ors ▁( PR R s ) ▁of ▁ph ag ocy tes ▁and ▁path ogen - associ ated ▁mole cular ▁patterns ▁( PA