( ( Organ systems ) ( ( studied ( include ( the ( ( integumentary ( , ( skeletal ( , ( ( muscular and ) nervous ) ) ) ) ) systems ) ) ) ) . ) )
(ROOT (S (NP (NN Organ) (NNS systems)) (VP (VBD studied) (VP (VB include) (NP (DT the) (ADJP (JJ integumentary) (, ,) (JJ skeletal) (, ,) (JJ muscular) (CC and) (JJ nervous)) (NNS systems)))) (. .)))
Organ systems studied include the integumentary, 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.