( ( and ( ( ( the ( ( integumentary ( , ( skeletal ( , ( ( muscular and ) nervous ) ) ) ) ) systems ) ) and ) ( their organs ) ) ) . )
(ROOT (S (VP (VB and) (NP (NP (DT the) (ADJP (JJ integumentary) (, ,) (JJ skeletal) (, ,) (JJ muscular) (CC and) (JJ nervous)) (NNS systems)) (CC and) (NP (PRP$ their) (NNS organs)))) (. .)))
and the integumentary, skeletal, muscular and nervous systems and their organs.
(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.