( ( The ( brain stem ) ) ( ( is ( ( ( ( ( a ( ( very important ) section ) ) ( of ( ( ( the brain ) , ) ( which ( controls ( processes ( like sleeping ) ) ) ) ) ) ) , ) or ) ( ( vital ( automatic functions ) ) ( of ( ( the body ) ( such ( as ( breathing ( or ( heart rate ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN brain) (NN stem)) (VP (VBZ is) (NP (NP (NP (DT a) (ADJP (RB very) (JJ important)) (NN section)) (PP (IN of) (NP (NP (DT the) (NN brain)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ controls) (NP (NP (NNS processes)) (PP (IN like) (NP (VBG sleeping)))))))))) (, ,) (CC or) (NP (NP (JJ vital) (JJ automatic) (NNS functions)) (PP (IN of) (NP (NP (DT the) (NN body)) (PP (JJ such) (IN as) (NP (NN breathing) (CC or) (NN heart) (NN rate)))))))) (. .)))
The brain stem is a very important section of the brain, which controls processes like sleeping, or vital automatic functions of the body such as breathing or heart rate.
(ROOT (S (NP (DT The) (NN brain) (NN stem)) (VP (VBZ regulates) (NP (NP (DT the) (NN rate)) (PP (IN of) (NP (NN breathing))))) (. .)))