he helped the understanding of the circulatory system :)

Michael Servetus

He was the first European to describe the function of pulmonary circulation

Michael Servetus has written:

'Syruporum vniuersa ratio' -- subject(s): Digestion, Early works to 1800, Medicine, Purgatives, Syrups, Therapeutic use

'In Leonardvm Fvchsivm apologia'

'Michael Servetus' -- subject(s): Astrology, Early works to 1800, Medicine

'Syruporum universa ratio, ad Galeni censuram diligenter expolita' -- subject(s): Digestion, Early works to 1800, Laxatives, Medicine, Syrups, Therapeutic use

that the blood flow through the heart and lungs

i got it from my science book