( Oxygen ( ( ( ( is ( ( ( transported ( from ( the alveoli ) ) ) ( to ( the ( pulmonary bloodstream ) ) ) ) ( by ( passive diffusion ) ) ) ) and ) ( is ( made ( available ( to tissues ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Oxygen)) (VP (VP (VBZ is) (VP (VBN transported) (PP (IN from) (NP (DT the) (NNS alveoli))) (PP (TO to) (NP (DT the) (JJ pulmonary) (NN bloodstream))) (PP (IN by) (NP (JJ passive) (NN diffusion))))) (CC and) (VP (VBZ is) (VP (VBN made) (S (ADJP (JJ available) (PP (TO to) (NP (NNS tissues)))))))) (. .)))
Oxygen is transported from the alveoli to the pulmonary bloodstream by passive diffusion and is made available to tissues.
(ROOT (S (NP (NNP Oxygen)) (VP (VBZ is) (VP (VBN transferred) (PP (IN into) (NP (DT the) (NN bloodstream))) (PP (IN by) (NP (JJ simple) (NN diffusion))))) (. .)))