An airway adapter structure including an airway adapter, the airway adapter comprising: (a) a substantially tubular first portion for releasably engaging a substantially tubular adapter, the substantially tubular first portion comprising: a wall having a first end portion, a second end portion, and a first bore defined therein, and a protrusion operatively coupled to the wall and having a second bore defined therethrough, wherein the protrusion is axially aligned with the first bore; (b) a longitudinally compressible member comprising a resilient sleeve secured over the protrusion such that a portion of the resilient sleeve extends beyond an end of the protrusion, the resilient sleeve including: a first skirt portion disposed over the protrusion and coupled to the substantially tubular first portion,, an annular transition connected to the first skirt portion and defining a transition bore of like diameter to the outer end of the second bore, a substantially teardrop-shaped compression segment extending axially from annular transition and defining therein a compression segment bore; a second skirt portion disposed on a longitudinally opposing side of the substantially teardrop-shaped compression segment from the first skirt portion, and an end cap having a barrel received within the second skirt portion, and an axial cap bore defined in the barrel and in fluid communication with the transition bore and the compression segment bore; and (c) a substantially tubular second portion coupled to the first end portion of the substantially tubular first portion, characterized in that the axial cap bore, the compression segment bore and the transition bore define a bore through the longitudinally compressible member that is in communication with the second bore so that, upon assembly of the airway adapter with a substantially tubular adapter by means of longitudinal movement of the two components toward one another, the bore in the longitudinally compressible member is in communication with the passage of the tubular adapter, and the end cap is configured to provide structural support for a distal tip of the resilient sleeve to prevent the tip of the resilient sleeve from collapsing in on itself when contacting the tubular adapter. (a) a substantially tubular first portion for releasably engaging a substantially tubular adapter, the substantially tubular first portion comprising: a wall having a first end portion, a second end portion, and a first bore defined therein, and a protrusion operatively coupled to the wall and having a second bore defined therethrough, wherein the protrusion is axially aligned with the first bore; a wall having a first end portion, a second end portion, and a first bore defined therein, and a protrusion operatively coupled to the wall and having a second bore defined therethrough, wherein the protrusion is axially aligned with the first bore; (b) a longitudinally compressible member comprising a resilient sleeve secured over the protrusion such that a portion of the resilient sleeve extends beyond an end of the protrusion, the resilient sleeve including: a first skirt portion disposed over the protrusion and coupled to the substantially tubular first portion,, an annular transition connected to the first skirt portion and defining a transition bore of like diameter to the outer end of the second bore, a substantially teardrop-shaped compression segment extending axially from annular transition and defining therein a compression segment bore; a second skirt portion disposed on a longitudinally opposing side of the substantially teardrop-shaped compression segment from the first skirt portion, and an end cap having a barrel received within the second skirt portion, and an axial cap bore defined in the barrel and in fluid communication with the transition bore and the compression segment bore; and a first skirt portion disposed over the protrusion and coupled to the substantially tubular first portion,, an annular transition connected to the first skirt portion and defining a transition bore of like diameter to the outer end of the second bore, a substantially teardrop-shaped compression segment extending axially from annular transition and defining therein a compression segment bore; a second skirt portion disposed on a longitudinally opposing side of the substantially teardrop-shaped compression segment from the first skirt portion, and an end cap having a barrel received within the second skirt portion, and an axial cap bore defined in the barrel and in fluid communication with the transition bore and the compression segment bore; and (c) a substantially tubular second portion coupled to the first end portion of the substantially tubular first portion,