( ( Systems studies ) ( ( include ( the ( skeletal ( , ( muscular ( and ( nervous systems ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Systems) (NNS studies)) (VP (VBP include) (NP (DT the) (JJ skeletal) (, ,) (JJ muscular) (CC and) (JJ nervous) (NNS systems))) (. .)))
Systems studies include the skeletal, muscular and nervous 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.