( ( ( Squeeze or ) hypobarotrauma ) ( ( is ( caused ( by ( ( a ( negative ( pressure difference ) ) ) ( across ( ( the ( ( wall ( of ( a ( non-collapsible air ) ) ) ) space ) ) ( -LRB- ( ( ( ( ( ( ( ( middle ear ) , ) sinuses ) , ) ( compressed lungs ) ) , ) ( hollow ( teeth etc. ) ) ) -RRB- ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Squeeze) (CC or) (NNP hypobarotrauma)) (VP (VBZ is) (VP (VBN caused) (PP (IN by) (NP (NP (DT a) (JJ negative) (NN pressure) (NN difference)) (PP (IN across) (NP (NP (DT the) (NAC (NN wall) (PP (IN of) (NP (DT a) (JJ non-collapsible) (NN air)))) (NN space)) (PRN (-LRB- -LRB-) (NP (NP (JJ middle) (NN ear)) (, ,) (NP (NNS sinuses)) (, ,) (NP (JJ compressed) (NNS lungs)) (, ,) (NP (FW hollow) (FW teeth) (FW etc.))) (-RRB- -RRB-)))))))) (. .)))
Squeeze or hypobarotrauma is caused by a negative pressure difference across the wall of a non-collapsible air space (middle ear, sinuses, compressed lungs, hollow teeth etc.).
(ROOT (S (SBAR (IN As) (S (NP (DT a) (NN diver)) (VP (VBZ descends)))) (, ,) (NP (NP (DT the) (NN increase)) (PP (IN in) (NP (NN pressure)))) (VP (VBZ causes) (NP (NP (DT the) (NN body) (POS 's)) (NN air) (NNS pockets)) (PP (IN in) (NP (NP (DT the) (NNS ears) (CC and) (NNS lungs)) (PP (TO to) (NP (NNS compress)))))) (. .)))