( ( When ( ( the ( emergency situation ) ) ( has ( passed ( the ( parasympathetic system ) ) ) ) ) ) ( ( ( ( takes over ) and ) ( decreases ( ( the ( heart ( and ( breathing ( rates ( and ( diverts blood ) ) ) ) ) ) ) ( ( supply back ) ( to ( activities ( such ( as ( digestion ( and ( food absorption ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (DT the) (NN emergency) (NN situation)) (VP (VBZ has) (VP (VBN passed) (NP (DT the) (JJ parasympathetic) (NN system)))))) (VP (VP (VBZ takes) (PRT (RP over))) (CC and) (VP (VBZ decreases) (S (NP (DT the) (NN heart) (CC and) (NN breathing) (NNS rates) (CC and) (NN diverts) (NN blood)) (VP (VB supply) (PRT (RP back)) (PP (TO to) (NP (NP (NNS activities)) (PP (JJ such) (IN as) (NP (NN digestion) (CC and) (NN food) (NN absorption))))))))) (. .)))
When the emergency situation has passed the parasympathetic system takes over and decreases the heart and breathing rates and diverts blood supply back to activities such as digestion and food absorption.
(ROOT (S (NP (NP (DT The) (JJ main) (NN function)) (PP (IN of) (NP (DT the) (JJ human) (NN digestive) (NN system)))) (VP (VBZ is) (S (VP (TO to) (VP (VB break) (PRT (RP down)) (NP (NP (NNS foods)) (PP (IN for) (NP (NN absorption)))) (PP (IN into) (NP (DT the) (NN blood))))))) (. .)))