Bone marrow is a rich source of pluripotent hematopoietic stem cells from which red blood cells, white blood cells, and platelets are formed. A tissue disruption and aspiration device having a flexible elongate shaft or cannula which is rotatable about its longitudinal axis may be introduced into a body cavity, e.g., the marrow cavity of a bone such as the iliac, through a single puncture opening. The cannula may be advanced through the cavity along various paths to aspirate the surrounding bone marrow into and through the cannula. The tissue disruptor located at the distal end of the cannula may be configured to rotate about the longitudinal axis of the shaft and agitate or disrupt the contacted tissue from its surrounding tissue matrix to thus facilitate aspiration of the bone marrow.The radiused tip enables the device to safely drill through the cancellous bone (bone marrow) without drilling through the cortical bone. When the tip encounters the hard cortical bone it changes direction and continues on through the bone marrow. So the tip has the ability to distinguish between cancellous and cortical bone and change direction in the marrow space.