<prompt> Spontaneously breathing infant- which breathing circuit to be used?Jackson Rees modification of Ayres T pieceMapleson A or Magills circuitMapleson C or waters to fro canisterBains circuit  <response>: Ans. is a i.e. Jackson Rees modification of Ayres T piece Circuit of choice for spontaneous ventilation in adult - Mapleson A Magill circuit Circuit of choice for controlled ventilation in adult - Mapleson D Bain circuit Circuit of choice for children - Type F, i.e. Jackson-Rees first choice and type E, i.e. Ayres T piece second choice Co-axial system- Mapelson C Waters to fro 