PROBLEM TO BE SOLVED: To provide a blood circuit in which the formation of a thrombus is suppressed.SOLUTION: A blood circuit 1 includes: blood circulation path 2 which includes a blood removal side flow path 21 for sending blood to a blood treatment part 7 and a blood return side flow path 22 for sending the blood which has passed through the blood treatment part 7 a replenishing liquid supply path 3 which merges into the blood circulation path 2 and always supplies a replenishing liquid S from a replenishing liquid source 3a to the blood circulation path 2 and a pretreatment liquid supply path 5 (priming liquid supply path) which merges into the replenishing liquid supply path 3 on the side closer to the replenishing liquid source 3a than a junction of the replenishing liquid supply path 3 and the blood circulation path 2, and which supplies a pretreatment liquid Pr (priming liquid) from a pretreatment liquid source 5a (priming liquid source)to the blood circulation path 2 through the replenishing liquid supply path 3.COPYRIGHT: (C)2015,JPO&INPIT【課題】血栓の発生が抑制された血液回路を提供することを目的とする。【解決手段】血液回路1は、血液を血液処理部7に送液する脱血側流路21と、前記血液処理部7を通過した血液を送液する返血側流路22と、を有する血液循環路2と、前記血液循環路2に合流し、補充液源3aからの補充液Sを前記血液循環路2に常時供給する補充液供給路3と、前記補充液供給路3と前記血液循環路2との合流点よりも前記補充液源3aに近い側で前記補充液供給路3に合流し、前処理液源5a(プライミング液源)からの前処理液Pr(プライミング液)を前記補充液供給路3を介して前記血液循環路2に供給する前処理液供給路5(プライミング液供給路)とを備える。【選択図】図1
