( ( ( ( ( ( ( The ( brain stem ) ) , ) ( which ( controls ( basic functions ) ) ) ) ( critical ( to life ) ) ) , ) ( such ( as ( ( ( ( ( ( heart rate ) , ) breathing ) , ) and ) sleeping ) ) ) ) . )
(ROOT (NP (NP (NP (DT The) (NN brain) (NN stem)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ controls) (NP (JJ basic) (NNS functions)))))) (ADJP (JJ critical) (PP (TO to) (NP (NN life)))) (, ,) (PP (JJ such) (IN as) (NP (NP (NN heart) (NN rate)) (, ,) (NP (NN breathing)) (, ,) (CC and) (NP (NN sleeping)))) (. .)))
The brain stem, which controls basic functions critical to life, such as heart rate, breathing, and sleeping.
(ROOT (S (NP (DT The) (NN brain) (NN stem)) (VP (VBZ regulates) (NP (NP (DT the) (NN rate)) (PP (IN of) (NP (NN breathing))))) (. .)))