A respiratory system is configured to pressurize and deliver a flow of respiratory gas to a patient's airways. The respiratory system includes a cushion configured to sealingly engage the patient's face and a blower mounted to the cushion and configured to pressurize a flow of respiratory gas. An interface structure is attached to an outlet of the blower and an aperture in the cushion. The interface structure forms a gas flow path between the cushion and the blower. The gas flow path is configured to deliver the pressurized respiratory gas from the blower through the aperture in the cushion. The gas flow path is also configured to vent exhaled gas from the aperture in the cushion to atmosphere. The respiratory system also includes headgear configured to support the cushion and the blower on the patient's face.