cles ▁was ▁their ▁volunt ary ▁motion . ▁ ▁On ▁this ▁claim , ▁he ▁dedu ced ▁that ▁the ▁heart ▁was ▁not ▁a ▁true ▁mus cle ▁due ▁to ▁the ▁obvious ▁invol unt ary ▁nature ▁of ▁its ▁motion . ▁ ▁He ▁identified ▁two ▁ch amb ers ▁and ▁two ▁at ria . ▁The ▁right ▁at rium ▁was ▁considered ▁a ▁continu ation ▁of ▁the ▁inferior ▁and ▁superior ▁v ena e ▁c ava e , ▁and ▁the ▁left ▁at rium ▁was ▁considered ▁a ▁continu ation ▁of ▁the ▁pul mon ary ▁ve in . ▁ ▁He ▁also ▁addressed ▁the ▁controvers ial ▁issue ▁of ▁the ▁heart ▁being ▁the ▁centre ▁of ▁the ▁soul . ▁ ▁He ▁wished ▁to ▁avoid ▁drawing ▁any ▁conclus ions ▁due ▁to ▁possible ▁conflict ▁with ▁contemporary ▁religious ▁belief s . ▁ ▁Again st ▁Gal en ' s ▁theory ▁and ▁many ▁belief s ▁he ▁also ▁discovered ▁that ▁there ▁was ▁no ▁hole ▁in ▁the ▁sept um ▁or ▁heart . ▁ ▁Other ▁achiev ements ▁▁ ▁V es al ius ▁dis pro ved ▁Gal en ' s ▁assertion ▁that ▁men ▁have ▁more ▁teeth ▁than ▁women . ▁ ▁V es al ius ▁introduced ▁the ▁notion ▁of ▁induction ▁of ▁the ▁extra ction ▁of ▁em py ema ▁through ▁surg ical ▁means . ▁ ▁Due ▁to ▁his ▁impress ive ▁study ▁of ▁the ▁human ▁sk ull ▁and ▁the ▁variations ▁in ▁its ▁features ▁he ▁is ▁said ▁to ▁have ▁been ▁responsible ▁for ▁the ▁launch ▁of ▁the ▁study ▁of ▁physical ▁anth rop ology . ▁ ▁V es al ius ▁always ▁encourag ed ▁his ▁students ▁to ▁check ▁their ▁find ings , ▁and