{HEAD ~ The bladder} has an annular form and a pair of opening extending through {TAIL ~ the bladder} in the axial direction of the bladder 
{ HEAD ~ The bladder } has an annular form and a pair of opening extending through { TAIL ~ the bladder } in the axial direction of the bladder
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH