( ( The penis ) ( ( ( consists mainly ) ( of ( ( three ( cylindrical bodies ) ) ( of ( ( ( erectile tissue ) ( -LRB- ( ( ( spongy tissue ) ( full ( of ( tiny ( blood vessels ) ) ) ) ) -RRB- ) ) ) ( that ( run ( ( the length ) ( of ( the organ ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS penis)) (VP (VBZ consists) (ADVP (RB mainly)) (PP (IN of) (NP (NP (CD three) (JJ cylindrical) (NNS bodies)) (PP (IN of) (NP (NP (JJ erectile) (NN tissue)) (PRN (-LRB- -LRB-) (NP (NP (JJ spongy) (NN tissue)) (PP (JJ full) (IN of) (NP (JJ tiny) (NN blood) (NNS vessels)))) (-RRB- -RRB-)) (SBAR (WHNP (WDT that)) (S (VP (VBP run) (NP (NP (DT the) (NN length)) (PP (IN of) (NP (DT the) (NN organ)))))))))))) (. .)))
The penis consists mainly of three cylindrical bodies of erectile tissue ( spongy tissue full of tiny blood vessels ) that run the length of the organ .
(ROOT (S (NP (DT The) (JJ human) (NNS penis)) (VP (VBZ contains) (NP (NP (DT the) (NN urethra)) (, ,) (CONJP (RB as) (RB well) (IN as)) (NP (NP (CD three) (NNS cylinders)) (PP (IN of) (NP (ADJP (RB spongy) (JJ erectile)) (NN tissue)))))) (. .)))
The human penis contains the urethra, as well as three cylinders of spongy erectile tissue.