( Embryonic ( ( ( blood ( is ( carried ( to ( ( the villi ) ( ( ( ( by ( ( the branches ) ( of ( the ( umbilical arteries ) ) ) ) ) , ) and ) ( after ( circulating ( through ( ( the capillaries ) ( of ( the villi ) ) ) ) ) ) ) ) ) ) ) ) , ) ( ( is ( ( returned ( to ( the embryo ) ) ) ( by ( the ( umbilical veins ) ) ) ) ) . ) ) )
(ROOT (S (NP (NNP Embryonic)) (PRN (S (NP (NN blood)) (VP (VBZ is) (VP (VBN carried) (PP (TO to) (NP (NP (DT the) (NN villi)) (PP (PP (IN by) (NP (NP (DT the) (NNS branches)) (PP (IN of) (NP (DT the) (JJ umbilical) (NNS arteries))))) (, ,) (CC and) (PP (IN after) (S (VP (VBG circulating) (PP (IN through) (NP (NP (DT the) (NNS capillaries)) (PP (IN of) (NP (DT the) (NN villi)))))))))))))) (, ,)) (VP (VBZ is) (VP (VBN returned) (PP (TO to) (NP (DT the) (NN embryo))) (PP (IN by) (NP (DT the) (JJ umbilical) (NNS veins))))) (. .)))
Embryonic blood is carried to the villi by the branches of the umbilical arteries, and after circulating through the capillaries of the villi, is returned to the embryo by the umbilical veins.
(ROOT (S (NP (JJ Portal) (NNS veins)) (VP (VBP carry) (NP (NP (NN blood)) (PP (IN between) (NP (NP (NNS pairs)) (PP (IN of) (NP (JJ capillary) (NNS beds))))))) (. .)))