▁capacity ▁of ▁flu ids ▁that ▁the ▁hyp oph ary nx ▁can ▁safely ▁hold ▁is ▁exceed ed , ▁then ▁this ▁excess ▁fluid ▁sp ills ▁into ▁the ▁l ary nx ▁and ▁from ▁there ▁into ▁the ▁l ungs . ▁Therefore , ▁these ▁ref lex es ▁prevent ▁levels ▁reaching ▁this ▁maximum ▁volume . ▁ ▁Since ▁both ▁the ▁dig est ive ▁system ▁and ▁the ▁resp ir atory ▁system ▁are ▁connected ▁by ▁the ▁ph ary nx , ▁there ▁are ▁many ▁problems ▁and ▁dise ases ▁that ▁occur ▁when ▁the ▁body ▁is ▁unable ▁to ▁reg ulate ▁passage ▁of ▁food ▁and ▁air ▁into ▁the ▁appropriate ▁tract s . ▁Perhaps ▁the ▁most ▁prevent able ▁cause ▁of ▁damage ▁to ▁these ▁ref lex es ▁origin ates ▁from ▁sm oking . ▁One ▁study ▁has ▁shown ▁that , ▁when ▁compared ▁to ▁non - sm ok ers , ▁the ▁threshold ▁volumes ▁( in ▁other ▁words ▁the ▁lowest ▁volume ▁at ▁which ▁one ▁of ▁these ▁ref lex es ▁is ▁triggered ) ▁for ▁both ▁the ▁ph ary ng o - upper ▁es oph age al ▁s ph inct er ▁contract ile ▁ref lex ▁and ▁ref lex ive ▁ph ary n ge al ▁sw allow ing ▁is ▁increased . ▁ ▁See ▁also ▁▁ ▁R etch ing , ▁also ▁known ▁as ▁dry ▁he aving ▁ ▁References ▁▁ ▁Category : H uman ▁thro at ▁Category : Ref lex es ▁Category : V om iting <0x0A> </s> ▁Major ▁General ▁Ralph ▁Cor b ett ▁Smith ▁( Nov ember ▁ 2 7 , ▁ 1 8 9 3 ▁– ▁January ▁ 2 1 , ▁ 1 9