( ( ( ( ( ( Brain Stem ) ( The ( brain stem ) ) ) , ) ( located ( at ( ( the base ) ( of ( the skull ) ) ) ) ) ) , ) ( ( is ( responsible ( for ( ( life-sustaining functions ) ( such ( as ( regulation ( of ( ( ( ( ( ( ( blood pressure ) , ) ( heart rate ) ) , ) breathing ) and ) ( body temperature ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NP (NNP Brain) (NNP Stem)) (NP (DT The) (NN brain) (NN stem))) (, ,) (VP (VBN located) (PP (IN at) (NP (NP (DT the) (NN base)) (PP (IN of) (NP (DT the) (NN skull)))))) (, ,)) (VP (VBZ is) (ADJP (JJ responsible) (PP (IN for) (NP (NP (JJ life-sustaining) (NNS functions)) (PP (JJ such) (IN as) (NP (NP (NN regulation)) (PP (IN of) (NP (NP (NN blood) (NN pressure)) (, ,) (NP (NN heart) (NN rate)) (, ,) (NP (NN breathing)) (CC and) (NP (NN body) (NN temperature)))))))))) (. .)))
Brain Stem The brain stem,  located at the base of the skull, is responsible for life-sustaining functions such as regulation of blood pressure, heart rate, breathing and body temperature.
(ROOT (S (NP (DT The) (NN brain) (NN stem)) (VP (VBZ regulates) (NP (NP (DT the) (NN rate)) (PP (IN of) (NP (NN breathing))))) (. .)))