( ( ( ( The integumentary ) , ) ( ( ( skeletal , ) and ) ( muscular systems ) ) ) . )
(ROOT (NP (NP (DT The) (NN integumentary)) (, ,) (NP (NP (NN skeletal)) (, ,) (CC and) (NP (JJ muscular) (NNS systems))) (. .)))
The integumentary, skeletal,          and muscular systems.
(ROOT (S (ADVP (RB Together)) (, ,) (NP (DT the) (JJ muscular) (CC and) (JJ skeletal) (NNS organs)) (VP (VBP are) (VP (VBN known) (PP (IN as) (NP (DT the) (JJ musculoskeletal) (NN system))))) (. .)))
Together, the muscular and skeletal organs are known as the musculoskeletal system.