( ( ( The ( ( autonomic nervous ) system ) ) ( -LRB- ( ANS -RRB- ) ) ) ( ( is ( responsible ( for ( maintaining homeostasis ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (ADJP (JJ autonomic) (JJ nervous)) (NN system)) (PRN (-LRB- -LRB-) (NP (NNP ANS)) (-RRB- -RRB-))) (VP (VBZ is) (ADJP (JJ responsible) (PP (IN for) (S (VP (VBG maintaining) (NP (NNS homeostasis))))))) (. .)))
The autonomic nervous system (ANS) is responsible for maintaining homeostasis.
(ROOT (S (NP (DT The) (JJ nervous) (NN system)) (VP (VBZ plays) (NP (NP (DT a) (JJ critical) (NN role)) (PP (IN in) (NP (NP (DT the) (NN regulation)) (PP (IN of) (NP (NN vascular) (NNS homeostasis))))))) (. .)))