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