<prompt> Which among the given options would produce most negative intrathoracic pressure?YawningFirst cry of a neonatesHigh pitch opera singingMullers manoeuvre  <response>: Under quiet breathing - At sta of inspiration normal ITP - -5 cm H2O At the end of inspiration normal ITP - -7 cm H2O Forceful breathing ITP: - deep sigh or a yawn- 30 cm H2O First cry of a neonate, first breath ITP - -60cmH2O Mullers maneuver - 100cm H2O Max negative ITP It is counter pa of Valsalva maneuver Muller maneuver is forced inspiratory effo against a closed glottis. 