( Next ( , ( ( ( surrounding ( the urethra ) ) ( like ( a ( small doughnut ) ) ) ) ( , ( ( is ( the ( prostate gland ) ) ) . ) ) ) ) )
(ROOT (S (NP (NNP Next)) (, ,) (S (VP (VBG surrounding) (NP (DT the) (NN urethra)) (PP (IN like) (NP (DT a) (JJ small) (NN doughnut))))) (, ,) (VP (VBZ is) (NP (DT the) (NN prostate) (NN gland))) (. .)))
Next, surrounding the urethra like a small doughnut, is the prostate gland.
(ROOT (S (NP (DT The) (NN prostate) (NN gland)) (VP (VBZ secretes) (NP (PRP$ its) (NNS products)) (ADVP (RB directly)) (PP (IN into) (NP (DT the) (NN urethra))) (PP (IN through) (NP (JJ several) (JJ small) (NNS ducts))))))