To provide a medical lumen body which can be bent by following bending movements of a body when a patient bends a part of the body and prevents buckling and kinking.SOLUTION: A sheath tube 110 includes: a long body part 120 having a distal end 121, a proximal end 123, and an intermediate part 125 in which a lumen 126 extending in an axial direction between the distal end and the proximal end is formed； a notch part 130 which is formed at least in a part of a wall part 127 defining the lumen of the intermediate part and extends in the axial direction； and a reinforcing member 150 arranged at least in a part of the intermediate part in a manner to be overlapped with at least a part of the notch part in the axial direction.SELECTED DRAWING: Figure 2【課題】患者が身体の一部を湾曲させた際に、身体を湾曲させる動作に追従して湾曲することができ、かつ、座屈やキンクすることを防止できる医療用管腔体を提供する。【解決手段】シースチューブ１１０は、先端１２１、基端１２３、および先端と基端との間で軸方向に延びる内腔１２６が形成された中間部１２５を備える長尺状の本体部１２０と、中間部の内腔を画定する壁部１２７の少なくとも一部に形成された軸方向に延びる切り欠き部１３０と、切り欠き部の少なくとも一部と軸方向において重なるように中間部の少なくとも一部に配置された補強部材１５０と、を備える。【選択図】図２
