( ( These chemicals ) ( ( ( ( primarily ( affect ( the ( ( parasympathetic nervous ) system ) ) ) ) and ) ( can ( act ( as ( anticholinergic agents ) ) ) ) ) . ) )
(ROOT (S (NP (DT These) (NNS chemicals)) (VP (VP (ADVP (RB primarily)) (VBP affect) (NP (DT the) (ADJP (JJ parasympathetic) (JJ nervous)) (NN system))) (CC and) (VP (MD can) (VP (VB act) (PP (IN as) (NP (JJ anticholinergic) (NNS agents)))))) (. .)))
These chemicals primarily affect the parasympathetic nervous system and can act as anticholinergic agents.
(ROOT (S (NP (DT The) (JJ parasympathetic) (NN system)) (VP (MD can) (ADVP (RB also)) (VP (VB be) (VP (VBN referred) (S (VP (TO to))) (PP (IN as) (NP (DT the) (JJ craniosacral) (NN system)))))) (. .)))