( ( ( ( ( The ( heart muscle ) ) , ) ( the MYOCARDIUM ) ) , ) ( ( ( ( ( is ( striated ( like ( ( the ( skeletal muscles ) ) ( of ( the body ) ) ) ) ) ) , ) but ) ( ( ( involuntary ( in action ) ) , ) ( like ( the ( smooth muscles ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN heart) (NN muscle)) (, ,) (NP (DT the) (NNP MYOCARDIUM)) (, ,)) (VP (VP (VBZ is) (VP (VBN striated) (PP (IN like) (NP (NP (DT the) (JJ skeletal) (NNS muscles)) (PP (IN of) (NP (DT the) (NN body))))))) (, ,) (CC but) (VP (VBD involuntary) (PP (IN in) (NP (NN action))) (, ,) (PP (IN like) (NP (DT the) (JJ smooth) (NNS muscles))))) (. .)))
The heart muscle, the MYOCARDIUM, is striated like the skeletal muscles of the body, but involuntary in action, like the smooth muscles.
(ROOT (S (PP (IN Like) (NP (JJ skeletal) (NN muscle))) (, ,) (NP (JJ cardiac) (NN muscle)) (VP (VBZ is) (VP (VBN striated))) (. .)))