Quick priming connectors for blood circuit

A connector system for use in priming a fluid circuit having a pump, a conduit having a first end coupled with the pump and a second end, a cannula having a first end, a second end configured to fluidly couple with a first fluid source, and a cannula lumen extending between the first and second ends of the cannula, the system comprising:

• a first connector configured to couple with the second end of the conduit, the first connector comprising a gas permeable membrane, a main lumen extending from the gas permeable membrane, and a secondary lumen having a first end configured to couple with a second fluid source and a second end in fluid communication with the main lumen;
• and
• a second connector configured to couple with the first end of the cannula, the second connector having an end configured to be inserted through the gas permeable membrane into the first connector, whereby fluid communication can be established between the main lumen of the first connector and the cannula lumen;
• wherein the first connector comprises a first surface and the end of the second connector comprises a second surface, the first and second surfaces configured to engage to provide a seamless lumen within the first connector at least at the location where the first and second surfaces engage.