<prompt> Circuit of choice for controlled ventilation -Magill circuitType CType DType E  <response>: Ans. is c i.e., Type DCircuit typeRequired fresh gas flowCommentsSpontaneousControlledType A Magill circuitEqual to minute volume 80 mlkgminVery high and difficult to predicto Circuit of choice for spontaneous ventilation.o Should not be used for controlled ventilationType B2 x minute volume2 - 2Vi minute volume Type C Waters to and fro2 x minute volume2 - 2Vi minute volumeo It is a coaxial systemType D Bain circuit2 - 3 x minute volume1 - 2 x minute volumeo Circuit to choice for controlled ventilation.o Most commonly used circuit,o Can also be used for spontaneous ventilation.Type E Ayres T-piece2-3 x minute volume3 x minute volumeo Circuit of 2nd choice in childrenType F Jackson-Rees circuit2-3 x minute volume2 x minute ventilationo Circuit of choice in childrenNote: - Coaxial system means both fresh gas tube and exhaled gas tube are placed in same axis, i.e., coaxial. Fresh gases are delivered through inner tube and exhaled gas are expired through ofter tube so that mixing of fresh gases and exhaled gases does not occur. 