( ( Responding ( to ( ( the ( renin-angiotensin system ) ) ( Like ( the ( nervous system ) ) ) ) ) ) ( , ( ( the RAS ) ( ( ( plays ( a ( key role ) ) ) ( in ( regulating CO. ) ) ) . ) ) ) )
(ROOT (S (S (VP (VBG Responding) (PP (TO to) (NP (NP (DT the) (JJ renin-angiotensin) (NN system)) (PP (IN Like) (NP (DT the) (JJ nervous) (NN system))))))) (, ,) (NP (DT the) (NNP RAS)) (VP (VBZ plays) (NP (DT a) (JJ key) (NN role)) (PP (IN in) (S (VP (VBG regulating) (NP (NNP CO.)))))) (. .)))
Responding to the renin-angiotensin system Like the nervous system, the RAS plays a key role in regulating CO.
(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))))))) (. .)))