主题：MedicalEnglish
Thebrainreceivesitsarterialsupplyfromtwopairsofvessels,thevertebralandinternalcarotidarteries,whichareinterconnectedinthecranialcavitytoproduceacerebralarterialcircle(ofWillis).
Vertebralarteries
Eachvertebralarteryarisesfromthefirstpartofeachsubclavianarteryinthelowerpartoftheneck,andpassessuperiorlythroughthetransverseforaminaoftheuppersixcervicalvertebrae.Onenteringthecranialcavitythroughtheforamenmagnum,eachvertebralarterygivesoffasmallmeningealbranch.
Continuingforward,thevertebralarterygivesrisetothreeadditionalbranchesbeforejoiningwithits北京治疗白癜风哪家比较好北京白癜风治疗的好医院
